The blast fungus, Magnaporthe oryzae, causes serious disease on a wide variety of grasses including rice, wheat and barley. The recognition of pathogens is an amazing ability of plants including strategies for displacing virulence effectors through the adaption of both conserved and variable pathogen elicitors. The pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) and effector-triggered immunity (ETI) were reported as two main innate immune responses in plants, where PTI gives basal resistance and ETI confers durable resistance. The PTI consists of extracellular surface receptors that are able to recognize PAMPs. PAMPs detect microbial features such as fungal chitin that complete a vital function during the organism's life. In contrast, ETI is mediated by intracellular receptor molecules containing nucleotide-binding (NB) and leucine rich repeat (LRR) domains that specifically recognize effector proteins produced by the pathogen. To enhance crop resistance, understanding the host resistance mechanisms against pathogen infection strategies and having a deeper knowledge of innate immunity system are essential. This review summarizes the recent advances on the molecular mechanism of innate immunity systems of rice against M. oryzae. The discussion will be centered on the latest success reported in plant-pathogen interactions and integrated defense responses in rice.

Ustilaginoidea virens is a common rice pathogen that can easily lead to a decline in rice quality and the production of toxins pose potential risks to human health. In this review, we present a comprehensive literature review of research since the discovery of rice false smut. We provide a comprehensive and, at times, critical overview of the main results and findings from related research, and propose future research directions. Firstly, we delve into the interaction between U. virens and rice, including the regulation of transcription factors, the process of U. virens infecting rice panicles, and the plant immune response caused by rice infection. Following that, we discuss the identification and characterization of mycotoxins produced by the pathogenic fungus, as well as strategies for disease management. We emphasize the importance of comprehensive agricultural prevention and control methods for the sustainable management of U. virens. This knowledge will update our understanding of the interaction between U. virens and rice plants, offering a valuable perspective for those interested in U. virens.

The aim of this review was to survey all fungal pathologists with an association with the journal Molecular Plant Pathology and ask them to nominate which fungal pathogens they would place in a 'Top 10' based on scientific/economic importance. The survey generated 495 votes from the international community, and resulted in the generation of a Top 10 fungal plant pathogen list for Molecular Plant Pathology. The Top 10 list includes, in rank order, (1) Magnaporthe oryzae; (2) Botrytis cinerea; (3) Puccinia spp.; (4) Fusarium graminearum; (5) Fusarium oxysporum; (6) Blumeria graminis; (7) Mycosphaerella graminicola; (8) Colletotrichum spp.; (9) Ustilago maydis; (10) Melampsora lini, with honourable mentions for fungi just missing out on the Top 10, including Phakopsora pachyrhizi and Rhizoctonia solani. This article presents a short resumé of each fungus in the Top 10 list and its importance, with the intent of initiating discussion and debate amongst the plant mycology community, as well as laying down a bench-mark. It will be interesting to see in future years how perceptions change and what fungi will comprise any future Top 10.© 2012 THE AUTHORS. MOLECULAR PLANT PATHOLOGY © 2012 BSPP AND BLACKWELL PUBLISHING LTD.

The Ustilaginoidea virens -rice pathosystem has been used as a model for flower-infecting fungal pathogens. The molecular biology of the interactions between U. virens and rice, with an emphasis on the attempt to get a deeper comprehension of the false smut fungus's genomes, proteome, host range, and pathogen biology, has been investigated. Meta-QTL analysis was performed to identify potential QTL hotspots for use in marker-assisted breeding. The Rice False Smut (RFS) caused by the fungus Ustilaginoidea virens currently threatens rice cultivators across the globe. RFS infects rice panicles, causing a significant reduction in grain yield. U. virens can also parasitize other hosts though they play only a minor role in its life cycle. Furthermore, because it produces mycotoxins in edible rice grains, it puts both humans and animals at risk of health problems. Although fungicides are used to control the disease, some fungicides have enabled the pathogen to develop resistance, making its management challenging. Several QTLs have been reported but stable gene(s) that confer RFS resistance have not been discovered yet. This review offers a comprehensive overview of the pathogen, its virulence mechanisms, the genome and proteome of U. virens, and its molecular interactions with rice. In addition, information has been compiled on reported resistance QTLs, facilitating the development of a consensus genetic map using meta-QTL analysis for identifying potential QTL hotspots. Finally, this review highlights current developments and trends in U. virens-rice pathosystem research while identifying opportunities for future investigations.© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.

The emerging pests and phytopathogens have reduced the crop yield and quality, which has threatened the global food security. Traditional breeding methods, molecular marker-based breeding approaches and use of genetically modified crops have played a crucial role in strengthening the food security worldwide. However, their usages in crop improvement have been highly limited due to multiple caveats. Genome editing tools like transcriptional activator-like effector nucleases and clustered regularly interspaced short palindromic repeats (CRISPR)-associated endonuclease Cas9 (CRISPR/Cas9) have effectively overcome limitations of the conventional breeding methods and are being widely accepted for improvement of crops. Among the genome editing tools, the CRISPR/Cas9 system has emerged as the most powerful tool of genome editing because of its efficiency, amicability, flexibility, low cost and adaptability. Accumulated evidences indicate that genome editing has great potential in improving the disease resistance in crop plants. In this review, we offered a brief introduction to the mechanisms of different genome editing systems and then discussed recent developments in CRISPR/Cas9 system-based genome editing towards enhancement of rice disease resistance by different strategies. This review also discussed the possible applications of recently developed genome editing approaches like CRISPR/Cas12a (formerly known as Cpf1) and base editors for enhancement of rice disease resistance.

Plant disease outbreaks pose significant risks to global food security and environmental sustainability worldwide, and result in the loss of primary productivity and biodiversity that negatively impact the environmental and socio-economic conditions of affected regions. Climate change further increases outbreak risks by altering pathogen evolution and host-pathogen interactions and facilitating the emergence of new pathogenic strains. Pathogen range can shift, increasing the spread of plant diseases in new areas. In this Review, we examine how plant disease pressures are likely to change under future climate scenarios and how these changes will relate to plant productivity in natural and agricultural ecosystems. We explore current and future impacts of climate change on pathogen biogeography, disease incidence and severity, and their effects on natural ecosystems, agriculture and food production. We propose that amendment of the current conceptual framework and incorporation of eco-evolutionary theories into research could improve our mechanistic understanding and prediction of pathogen spread in future climates, to mitigate the future risk of disease outbreaks. We highlight the need for a science-policy interface that works closely with relevant intergovernmental organizations to provide effective monitoring and management of plant disease under future climate scenarios, to ensure long-term food and nutrient security and sustainability of natural ecosystems.© 2023. Springer Nature Limited.

The pattern recognition receptor XA21 confers developmentally-regulated resistance to bacterial blight disease of rice caused by Xanthomonas oryzae pv. oryzae. Under normal conditions, XA21 plants are susceptible when inoculated 2weeks after germination and become fully resistant as they mature (after six-week-old). We report here that XA21-mediated resistance can be fully activated when the juvenile plants are grown at 27 degrees C under fluorescent light. Once transferred back to 31 degrees C under the same light intensity, XA21 seedlings lose the gained resistance. Temperature shift experiments indicate that high temperature treatment can suppress activated XA21 resistance. We also show that abundance of the XA21 protein is not significantly influenced by the temperature changes. These results highlight an interplay between development and temperature in this immune system. Full activation of resistance at juvenile stage will greatly facilitate the studies of XA21 immunity.

【目的】 探究水稻减数分裂期高温如何影响苯丙烷类代谢，并分析其与水稻耐热性的关系。【方法】 以N22、广陆矮15、SDWG005、全两优681、Y两优900、Y两优1号、两优培九和绵恢101(MH101)等8种耐热和不耐热水稻品种为试验材料，设置常温和高温处理，分析减数分裂期高温胁迫对水稻的花粉活力与苯丙烷类代谢关键酶活性、木质素、总黄酮及总酚等主要代谢产物含量之间的相关性；并进一步选择极端耐高温的SDWG005和极端不耐高温的MH101为材料分析苯丙烷类代谢、碳水化合物代谢和抗氧化系统对水稻耐热性的影响。【结果】 1) 与对照相比，高温显著降低水稻花粉活力和颖花受精率，不同的水稻品种受高温影响后，花粉活力和颖花受精率的降幅不同。2) 高温显著增加颖花中肉桂酸-4-羟化酶和4-香豆酸辅酶A连接酶活性以及木质素、总黄酮和总酚的含量，且耐热品种增幅高于敏感品种。3) 高温下花粉活力与肉桂酸-4-羟化酶活性、木质素含量显著相关，颖花受精率与木质素含量以及木质素含量与类黄酮含量极显著相关。4) 与MH101相比，SDWG005小穗颖壳中木质素受高温显著诱导积累，且高温下能够维持较高细胞壁过氧化物酶活性。5) 与MH101相比，SDWG005颖花在高温下能够维持较高过氧化物酶、超氧化物歧化酶和抗坏血酸氧化酶活性，进而减少颖花中过氧化氢和丙二醛的积累。高温下SDWG005颖花中淀粉含量更高，酸性转化酶、蔗糖合酶及ATPase基因的表达量显著增加。【结论】 减数分裂期高温促进颖花中苯丙烷类代谢关键酶活性的上升和代谢产物含量的增加，耐热品种高温下能够积累较多的木质素和类黄酮，具有较高抗氧化酶活性，同时蔗糖代谢和能量产生效率较高，从而具有较强的耐热性。

【Objective】 Our purposes are to investigate how high temperature during rice meiosis affects phenylpropane metabolism and analyze its relationship with heat tolerance of rice. 【Methods】 Eight rice varieties differed in heat tolerance including N22, GLA15 (Guanglu’ai 15), SDWG005, QLY681 (Quanliangyou 681), YLY900 (Y Liangyou 900), YLY1 (Y Liangyou 1), LYP9 (Liangyoupeijiu), and MH101 (Mianhui 101) were used as experimental materials and exposed to room temperature and high temperature for 5 days. The correlations between activities of key enzymes in phenylpropane metabolism and main metabolite contents such as lignin, total flavonoids and total phenols were analyzed as well as the fertility of rice under high temperature stress during the meiotic stage. SDWG005 (heat resistant) and MH101 (heat sensitive) were used as experimental materials to analyze the effects of phenylpropane metabolism, carbohydrate metabolism and antioxidant defense system on heat tolerance of rice. 【Results】 1) Compared with the control, the pollen vitality and fertilization rate of spikelets decreased significantly to various extents at high temperature. 2) HT(high temperature) significantly increased the activities of cinnamate-4-hydroxylase and 4-coumaric acid coenzyme A ligase, as well as the accumulation of lignin, flavonoids and total phenols in spikelets, with resistant varieties registering a higher growth than sensitive ones. 3) Correlation analysis showed that in response to HT pollen activity was significantly correlated with cinnamate-4-hydroxylase activity and lignin content, spikelet fertility was significantly correlated with lignin content, and lignin content was significantly correlated with flavonoid content. 4) Compared with MH101, lignin accumulation in the glumes of SDWG005 was significantly induced under HT. And higher cell wall peroxidase activities were maintained in SDWG005 under HT. 5) Compared with MH101, SDWG005 could maintain higher antioxidant enzyme activities under HT, resulting in less accumulation of H2O2 and malondialdehyde. Under HT, the starch level in SDWG005 flowers was higher, and the expression levels of genes involved in acid invertase, sucrose synthase and ATPase were significantly upregulated. 【Conclusion】 High temperature stress increases the key enzyme activities and metabolite contents in the phenylpropanoid pathway in spikelets during the meiosis stage. The resistant variety accumulates more lignin and flavonoids during HT, has higher antioxidant enzyme activities, higher sucrose metabolism and energy utilization efficiency, thereby improving heat tolerance.

南方水稻黑条矮缩病为白背飞虱传播的一种毁灭性的水稻病毒病。文章根据2009~2016年化州地区南方水稻黑条矮缩病发生和危害情况,通过对南方水稻黑条矮缩病病害症状和介体昆虫的认识,分析南方水稻黑条矮缩病发生的轻重与介体数量、毒源量、水稻品种、种植方式、水稻播期、秧田位置及气候条件等因素有关。提出全面实施“防控技术前移,切断毒源,治虫防病”的防治策略；形成适合粤西稻区特点的南方水稻黑条矮缩病综合防控的技术体系,并在生产上推广应用,有效预防控制了南方水稻黑条矮缩病发生流行危害,取得了显著的社会经济效益。

Southern rice black-streaked dwarf virus (SRBSDV) is a kind of ruinous rice virus disease transmitted by the whitebacked planthopper. Basing on the occurrence and harm of SRBSDV in Huazhou district from 2009 to 2016, with recognization of the disease symptom and insect vector of SRBSDV, the essay analyzes that the severity of SRBSDV is related to vector numbers, viral source capacity, rice species, planting patterns, rice sowing period, seedling bed position and climate condition. The control strategy, which includes putting forward prevention and control technology, cutting off viral source, defending against insects, is proposed for comprehensive application. The synthetical preventing SRBSDV technical system which adapts to rice region in the western part of Guangdong province is implemented. The technical system is promoted and applied in production. With the measures above, the epidemic risks of SRBSDV can be prevented and controlled to obtain remarkable social and economic benefits.

Plant-specific group VII Ethylene Response Factor (ERF) transcription factors have emerged as pivotal regulators of flooding and low oxygen responses. In rice (Oryza sativa), these proteins regulate contrasting strategies of flooding survival. Recent studies on Arabidopsis thaliana group VII ERFs show they are stabilized under hypoxia but destabilized under oxygen-replete conditions via the N-end rule pathway of targeted proteolysis. Oxygen-dependent sequestration at the plasma membrane maintains at least one of these proteins, RAP2.12, under normoxia. Remarkably, SUB1A, the rice group VII ERF that enables prolonged submergence tolerance, appears to evade oxygen-regulated N-end rule degradation. We propose that the turnover of group VII ERFs is of ecological relevance in wetland species and might be manipulated to improve flood tolerance of crops.Copyright © 2011 Elsevier Ltd. All rights reserved.

Microbial communities play a pivotal role in the functioning of plants by influencing their physiology and development. While many members of the rhizosphere microbiome are beneficial to plant growth, also plant pathogenic microorganisms colonize the rhizosphere striving to break through the protective microbial shield and to overcome the innate plant defense mechanisms in order to cause disease. A third group of microorganisms that can be found in the rhizosphere are the true and opportunistic human pathogenic bacteria, which can be carried on or in plant tissue and may cause disease when introduced into debilitated humans. Although the importance of the rhizosphere microbiome for plant growth has been widely recognized, for the vast majority of rhizosphere microorganisms no knowledge exists. To enhance plant growth and health, it is essential to know which microorganism is present in the rhizosphere microbiome and what they are doing. Here, we review the main functions of rhizosphere microorganisms and how they impact on health and disease. We discuss the mechanisms involved in the multitrophic interactions and chemical dialogues that occur in the rhizosphere. Finally, we highlight several strategies to redirect or reshape the rhizosphere microbiome in favor of microorganisms that are beneficial to plant growth and health. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

Plants often encounter unfavorable environmental conditions because of their sessile lifestyle. These adverse factors greatly affect the geographic distribution of plants, as well as their growth and productivity. Drought stress is one of the premier limitations to global agricultural production due to the complexity of the water-limiting environment and changing climate. Plants have evolved a series of mechanisms at the morphological, physiological, biochemical, cellular, and molecular levels to overcome water deficit or drought stress conditions. The drought resistance of plants can be divided into four basic types-drought avoidance, drought tolerance, drought escape, and drought recovery. Various drought-related traits, including root traits, leaf traits, osmotic adjustment capabilities, water potential, ABA content, and stability of the cell membrane, have been used as indicators to evaluate the drought resistance of plants. In the last decade, scientists have investigated the genetic and molecular mechanisms of drought resistance to enhance the drought resistance of various crops, and significant progress has been made with regard to drought avoidance and drought tolerance. With increasing knowledge to comprehensively decipher the complicated mechanisms of drought resistance in model plants, it still remains an enormous challenge to develop water-saving and drought-resistant crops to cope with the water shortage and increasing demand for food production in the future.

Plant aquaporins are recently noted biological resource with a great potential to improve crop growth and defense traits. Here, we report functional modulation of Oryza sativa aquaporin OsPIP1;3 to enhance rice photosynthesis and grain production and to control bacterial blight and leaf streak, the most devastating world-wide bacterial diseases in the crop. We characterize OsPIP1;3 as a physiologically relevant CO -transporting facilitator, which supports 30% of rice photosynthesis on average. This role is nullified by OsPIP1;3 interaction with the bacterial protein Hpa1, an essential component of the type-III translocon that supports translocation of the bacterial type-III effectors PthXo1 and TALi into rice cells to induce leaf blight and streak, respectively. Hpa1 binding shifts OsPIP1;3 from CO transport to the effector translocation, aggravates bacterial virulence, but sacrifices rice photosynthesis. On the contrary, the external application of isolated Hpa1 to rice plants effectively prevents OsPIP1;3 from interaction with Hpa1 secreted by the bacteria that are infecting the plants. The inhibition of OsPIP1;3-Hpa1 interaction reverts OsPIP1;3 from the effector translocation to CO transport, abrogates bacterial virulence, and meanwhile induces defense responses in rice. These beneficial effects can combine to confer photosynthesis enhancement by 29-30%, bacterial disease reductions by 58-75%, and grain yield increase between 11% and 34%, in different rice varieties investigated in small-scale field trails implemented during the past years. Our results suggest that crop productivity and immunity can be coordinated by modulating physiological and pathological functions of a single aquaporin to break the growth-defense tradeoff barrier.This article is protected by copyright. All rights reserved.

The effect of elevated atmospheric CO(2) concentration on rice blast and sheath blight disease severity was studied in the field in northern Japan for 3 years. With free-air CO(2) enrichment (FACE), rice plants were grown in ambient and elevated ( approximately 200 to 280 mumol mol(-1) above ambient) CO(2) concentrations, and were artificially inoculated with consist of Magnaporthe oryzae. Rice plants grown in an elevated CO(2) concentration were more susceptible to leaf blast than those in ambient CO(2) as indicated by the increased number of leaf blast lesions. Plants grown under elevated CO(2) concentration had lower leaf silicon content, which may have contributed to the increased susceptibility to leaf blast under elevated CO(2) concentrations. In contrast to leaf blast, panicle blast severity was unchanged by the CO(2) enrichment under artificial inoculation, whereas it was slightly but significantly higher under elevated CO(2) concentrations in a spontaneous rice blast epidemic. For naturally occurring epidemics of the sheath blight development in rice plants, the percentage of diseased plants was higher under elevated as opposed to ambient CO(2) concentrations. However, the average height of lesions above the soil surface was similar between the treatments. One hypothesis is that the higher number of tillers observed under elevated CO(2) concentrations may have increased the chance for fungal sclerotia to adhere to the leaf sheath at the water surface. Consequently, the potential risks for infection of leaf blast and epidemics of sheath blight would increase in rice grown under elevated CO(2) concentration.

The leaf anatomy, photosynthetic system parameters and accumulation of carbohydrates were determined at different times for Bipolaris oryzae pathogenesis in two rice cultivars (BRS Querencia and Inov CL), grown in an environment with 400 ppm or 700 ppm of atmospheric CO2. The results demonstrated that the plants exposed to 700 ppm underwent changes in anatomical characteristics (reduction in parenchyma thickness and size of bulliform cells), photosynthetic parameters (increased carbon assimilation rate, leaf intercellular CO2 concentration and water use efficiency, and reduction of stomatal conductance to water vapor, transpiration rate and carboxylation efficiency), and carbohydrate accumulation (increased concentration of soluble sugars and starch), when compared to plants at 400 ppm. Therefore, the changes in morphological traits of the leaf and the accumulation of carbohydrates, which were stimulated in the rice plants by increased CO2 concentration (700 ppm), were associated with less severe brown spot, caused by B. oryzae.

糖不仅是植物细胞的碳源、能源和结构物质,也是一种信号分子,在植物生长发育及响应逆境胁迫中起重要作用。非生物逆境如高温、低温、干旱、盐渍和重金属胁迫是限制作物产量的主要胁迫因子,糖作为信号分子在植物响应这些胁迫因子中的确切机理,尚未清楚。基于植物中糖信号转导途径及其在植物耐逆性形成中作用的最新研究进展,归纳了植物中分别依赖己糖激酶（HXK）、G蛋白信号1调节子（RGS1）、糖酵解（EMP）和磷酸戊糖途径（PPP）的糖信号转导途径,讨论了糖信号在植物耐逆性包括耐热性、耐冷性、耐旱性、耐盐性和重金属胁迫耐性形成中的作用,最后展望了糖信号在植物生物学领域的研究方向。

Diffusion of CO from the leaf intercellular air space to the site of carboxylation (g ) is a potential trait for increasing net rates of CO assimilation (A ), photosynthetic efficiency, and crop productivity. Leaf anatomy plays a key role in this process; however, there are few investigations into how cell wall properties impact g and A. Online carbon isotope discrimination was used to determine g and A in Oryza sativa wild-type (WT) plants and mutants with disruptions in cell wall mixed-linkage glucan (MLG) production (CslF6 knockouts) under high- and low-light growth conditions. Cell wall thickness (T ), surface area of chloroplast exposed to intercellular air spaces (S ), leaf dry mass per area (LMA), effective porosity, and other leaf anatomical traits were also analyzed. The g of CslF6 mutants decreased by 83% relative to the WT, with c. 28% of the reduction in g explained by S. Although A /LMA and A /Chl partially explained differences in A between genotypes, the change in cell wall properties influenced the diffusivity and availability of CO. The data presented here indicate that the loss of MLG in CslF6 plants had an impact on g and demonstrate the importance of cell wall effective porosity and liquid path length on g.© 2018 The Authors. New Phytologist © 2018 New Phytologist Trust.

Changes in stratospheric ozone and climate over the past 40-plus years have altered the solar ultraviolet (UV) radiation conditions at the Earth's surface. Ozone depletion has also contributed to climate change across the Southern Hemisphere. These changes are interacting in complex ways to affect human health, food and water security, and ecosystem services. Many adverse effects of high UV exposure have been avoided thanks to the Montreal Protocol with its Amendments and Adjustments, which have effectively controlled the production and use of ozone-depleting substances. This international treaty has also played an important role in mitigating climate change. Climate change is modifying UV exposure and affecting how people and ecosystems respond to UV; these effects will become more pronounced in the future. The interactions between stratospheric ozone, climate and UV radiation will therefore shift over time; however, the Montreal Protocol will continue to have far-reaching benefits for human well-being and environmental sustainability.

In order to explore the efficacy of a new type of ozone sterilizer device in controlling vegetable seedling diseases and its impact on the growth of vegetables, experiments on disease control were conducted in greenhouses using tomato leaf mold, cucumber powdery mildew, and cabbage dampingoff as test subjects. In one of the greenhouses, the ozone plant protection machine was suspended from the greenhouse ceiling and used highvoltage discharge to generate ozone, which was then rapidly diffused throughout the facility using a highspeed fan and special air duct. The machine can be controlled remotely for realtime adjustment of ozone release, and its operation status can be constantly monitored using a mobile app. Thus, the ozone concentration in a facility can be dynamically adjusted to better control vegetable diseases. Compared with conventionally managed greenhouses without disease control measures, the incidence rates of tomato leaf mold, cucumber powdery mildew, and cabbage dampingoff in the greenhouse with the installed multifunctional plant protection machine were controlled at 5.2%, 4.7%, and 17.4%, which is 12.2%, 9.8%, and 1.8% lower, respectively, than the incidence rates in the conventionally managed greenhouse. The results showed that ozone had favorable control effects on tomato leaf mold and cucumber powdery mildew and showed certain control effects on cabbage dampingoff. Moreover, the ozone had no adverse effects on the normal growth of the vegetables. These data provide a reference for the wide use of ozone to control vegetable diseases in greenhouses.

Tropospheric ozone (O) is among the most damaging air pollutant to plants. Plants alter the atmospheric O concentration in two distinct ways: (i) by the emission of volatile organic compounds (VOCs) that are precursors of O and (ii) by dry deposition, which includes diffusion of O into vegetation through stomata and destruction by nonstomatal pathways. Isoprene, monoterpenes, and higher terpenoids are emitted by plants in quantities that alter tropospheric O. Deposition of O into vegetation is related to stomatal conductance, leaf structural traits, and the detoxification capacity of the apoplast. The biochemical fate of O once it enters leaves and reacts with aqueous surfaces is largely unknown, but new techniques for the tracking and identification of initial products have the potential to open the black box.Published by Elsevier Ltd.

Tropospheric ozone concentrations have been rising across Asia, and will continue to rise during the 21st century. Ozone affects rice yields through reductions in spikelet number, spikelet fertility, and grain size. Moreover, ozone leads to changes in rice grain and straw quality. Therefore the breeding of ozone tolerant rice varieties is warranted. The mapping of quantitative trait loci (QTL) using bi-parental populations identified several tolerance QTL mitigating symptom formation, grain yield losses, or the degradation of straw quality. A genome-wide association study (GWAS) demonstrated substantial natural genotypic variation in ozone tolerance in rice, and revealed that the genetic architecture of ozone tolerance in rice is dominated by multiple medium and small effect loci. Transgenic approaches targeting tolerance mechanisms such as antioxidant capacity are also discussed. It is concluded that the breeding of ozone tolerant rice can contribute substantially to the global food security, and is feasible using different breeding approaches. Copyright © 2014 Elsevier Ltd. All rights reserved.

Rapid stomatal closure induced by changes in the environment, such as elevation of CO2, reduction of air humidity, darkness, and pulses of the air pollutant ozone (O3), involves the SLOW ANION CHANNEL1 (SLAC1). SLAC1 is activated by OPEN STOMATA1 (OST1) and Ca(2+)-dependent protein kinases. OST1 activation is controlled through abscisic acid (ABA)-induced inhibition of type 2 protein phosphatases (PP2C) by PYRABACTIN RESISTANCE/REGULATORY COMPONENTS OF ABA RECEPTOR (PYR/RCAR) receptor proteins. To address the role of signaling through PYR/RCARs for whole-plant steady-state stomatal conductance and stomatal closure induced by environmental factors, we used a set of Arabidopsis (Arabidopsis thaliana) mutants defective in ABA metabolism/signaling. The stomatal conductance values varied severalfold among the studied mutants, indicating that basal ABA signaling through PYR/RCAR receptors plays a fundamental role in controlling whole-plant water loss through stomata. PYR/RCAR-dependent inhibition of PP2Cs was clearly required for rapid stomatal regulation in response to darkness, reduced air humidity, and O3. Furthermore, PYR/RCAR proteins seem to function in a dose-dependent manner, and there is a functional diversity among them. Although a rapid stomatal response to elevated CO2 was evident in all but slac1 and ost1 mutants, the bicarbonate-induced activation of S-type anion channels was reduced in the dominant active PP2C mutants abi1-1 and abi2-1. Further experiments with a wider range of CO2 concentrations and analyses of stomatal response kinetics suggested that the ABA signalosome partially affects the CO2-induced stomatal response. Thus, we show that PYR/RCAR receptors play an important role for the whole-plant stomatal adjustments and responses to low humidity, darkness, and O3 and are involved in responses to elevated CO2.

Recent studies have suggested that ethylene enhances host resistance to fungal pathogen Magnaporthe oryzae, the causal agent of rice blast disease. Among the six 1-aminocyclopropane-1-carboxylic acid synthase genes in rice, OsACS1 and OsACS2 are induced within 24 h of inoculation by M. oryzae. This induction occurs simultaneously with an increase in ethylene production that is noticeable 12 h postinoculation. The purpose of this study was to examine the dynamics of ethylene production and signaling in wild type and RNA interference-mediated suppression lines deficient in ethylene production (acs2) or signaling (eil1) after challenge with M. oryzae as well as fungal cell-wall elicitors. Ethylene-insensitive mutant lines show an attenuated basal defense response including lower basal expression of the genes encoding a chitin-binding receptor, pathogenesis-related (PR) proteins, and the enzymes involved in the synthesis of diterprenoid phytoalexins, a reduction on early hypersensitive response (HR)-like cell death, and reduced incidence of callose deposition. Ethylene-deficient mutants showed an intermediate phenotype, with a significant reduction in expression of defense-related genes and callose deposition, but only a slight reduction in HR-like cell death. As a result, all ethylene-insensitive mutants show increased susceptibility to M. oryzae, whereas the ethylene-deficient lines show a slight but less significant increase in disease severity. These results show that ethylene signaling and, to some extent, ethylene production are required for rice basal resistance against the blast fungus Magnaporthe oryzae.

以抗病性不同的一对水稻近等基因系——感病CO39和抗病C101LACPi-1)为实验材料，在水培条件下研究了施硅和稻瘟病接菌对水稻根系和叶片抗性物质有机酸含量的影响，揭示硅提高水稻对稻瘟病抗性的机理。结果表明：接菌条件下硅处理显著降低了2个基因型材料的叶片反丁烯二酸、柠檬酸的含量，而增加了叶片中草酸、顺丁烯二酸的含量；加硅显著降低接菌后第3天的CO39叶片酒石酸含量，但增加了C101LAC(Pi-1)接菌后第7天的叶片酒石酸含量；硅处理还显著增加了根系中苹果酸和草酸的含量；各种有机酸在水稻植株体内的分布也不尽相同，如柠檬酸主要分布在叶片中，苹果酸主要分布在根系中，顺丁烯二酸、反丁烯二酸、酒石酸和草酸在叶片和根系中都有分布。研究表明，硅可能通过影响植株体内的有机酸代谢而增强稻瘟病的抗性。

This review focuses on relationships between the abscission process (organ shedding) and other related processes like shattering, senescence, pathogen defense, and drought stress with emphasis on how the relationships might be exploited to advance their respective fields. Shared molecular components provide a means for cross-talk between processes as well as a means for knowledge transfer between fields. The review briefly covers how fundamental abscission molecular mechanisms can be used for crop improvement. We cover seed abscission and shattering in rice, cereals, and beans as well as abscission in Arabidopsis and tomato. The review provides a set of five guidelines that can be used to direct future cell separation research. Finally, we give our perspective on methods and technologies that are likely to advance the abscission field.Copyright © 2019 Elsevier B.V. All rights reserved.

滨海盐碱地水稻生产受限于淡水资源和水利基础设施，盐害和干旱往往交织出现，极易遭受盐−旱复合胁迫，严重制约了滨海盐碱地水稻丰产优质目标的实现。全面剖析盐、干旱胁迫及其复合胁迫对水稻产量和品质形成的影响及其生理机制，可为滨海盐碱地水稻高产与品质调优栽培提供科学支撑。本文概述了盐、干旱及其复合胁迫对水稻生长发育、产量形成和稻米品质的影响，从渗透调节、离子平衡、光合作用、抗氧化酶系统、内源激素、蔗糖-淀粉代谢关键酶活性和分子机制等方面阐述其影响水稻产量和品质形成的作用机制，从耐盐耐旱品种选育及栽培调控等方面提出了减轻水稻盐/干旱胁迫的调控措施，为今后深入开展水稻耐盐和干旱的研究提出建议。

The production of rice in coastal saline-alkali lands is constrained by limited freshwater resources and water infrastructure. The presence of salinity damage and drought, often occurring together, renders rice production in these areas highly susceptible to combined salinity-drought stress, significantly impeding the attainment of high yield and quality in rice in coastal saline-alkali lands. A comprehensive analysis of the impacts of salinity damage, drought, and their combined stresses on rice yield and quality formation, along with their physiological mechanisms, can offer scientific backing for optimizing high-yield and quality rice cultivation in coastal saline-alkali lands. This article presents an overview of the effects of salinity damage, drought, and their combined stresses on the growth, development, yield formation, and grain quality of rice. The mechanisms underlying their influence on rice yield and quality formation are elucidated, focusing on osmotic regulation, ion balance, photosynthetic functions, antioxidant enzyme systems, endogenous hormones, key enzyme activities related to sucrose-starch metabolism, and molecular mechanisms. Recommendations are provided for the selection of salinity- and drought-tolerant varieties, as well as cultivation practices to mitigate salinity and drought stress in rice. Lastly, suggestions are proposed for further research on salinity and drought stress in rice.

水稻是全球最重要的粮食作物之一，其生长过程需要大量水分。随着全球气候变暖，干旱成为其产量的重要限制因素。因此，本文结合近些年的研究成果从形态（根系和地上部）、生理（气孔、蒸腾作用、光合作用和水分利用率）、生化（植物激素、脯氨酸等渗透调节剂和抗氧化剂）及分子水平（抗旱基因的表达水平）综述了水稻在干旱胁迫下的自我保护机制，可为全面了解水稻抗旱机制和选育抗旱品种提供参考。

Rice is one of the most important food crops globally, and its growth requires more water than many other crops. With global warming, drought has emerged as the main factor limiting crop yields. Therefore, based on recent research achievements, this paper summarizes the self-protection mechanisms of rice under drought stress. This includes aspects such as morphology (plant height, roots, leaves, number of tillers, and plant biomass), physiology (stomata, transpiration, photosynthesis, and water use efficiency), biochemistry (plant hormones, proline, other osmotic regulators, and antioxidants), and molecular biology (expression levels of drought resistance genes). The aim is to comprehensively understand rice's drought resistance mechanisms and provide a reference for breeding drought-resistant varieties

近年来，优良食味粳稻品种南粳46、南粳5055和南粳9108在江苏等地大面积推广，促进了优质稻米产业的发展。但这些品种均不抗稻瘟病，且缺乏适合在淮北地区种植的中熟中粳型优良食味粳稻品种。本研究以同时携带稻瘟病抗性基因Pi-ta和Pi-b的江苏抗病、高产粳稻品种武粳15为母本，携带低直链淀粉含量基因Wx-mq的优良食味粳稻品种南粳5055为父本配置杂交组合进行聚合育种。利用Pi-ta和Pi-b基因的分子标记多重PCR体系以及Wx-mq基因的四引物扩增受阻突变体系PCR检测技术，分别在不同的分离世代对目标基因位点进行检测，结合田间多代选育、抗性鉴定和籽粒胚乳外观鉴定，成功地将Pi-ta、Pi-b和Wx-mq基因聚合于一体，选育出稻瘟病抗性好、食味品质优、产量高的水稻新品系“南粳0051”，适合在江苏省淮北地区种植。本研究将三套自主研发的PCR检测体系成功应用于分子标记辅助选择，不仅为水稻多基因聚合育种提供了快捷、高效的选择方法，也为水稻抗病、优质育种创制了新的种质资源。

Varalu is an early maturing rice variety widely grown in the rainfed ecosystem preferred for its grain type and cooking quality. However, the yield of Varalu is substantially low since it is being affected by reproductive drought stress along with the blast disease. The genetic improvement of Varalu was done by introgressing a major yield QTL, qDTY12.1, along with two major blast resistance genes i.e. Pi54 and Pi1 through marker-assisted backcross breeding. Both traits were transferred till BC2 generation and intercrossing was followed to pyramid the two traits. Stringent foreground selection was carried out using linked markers as well as peak markers (RM28099, RM28130, RM511 and RM28163) for the targeted QTL (qDTY12.1), RM206 for Pi54 and RM224 for Pi1. Extensive background selection was done using genome-wide SSR markers. Six best lines (MSM-36, MSM-49, MSM-53, MSM-57, MSM-60 and MSM-63) having qDTY12.1 and two blast resistance genes in homozygous condition with recurrent parent genome of 95.0%?96.5% having minimal linkage drag of about 0.1 to 0.7 Mb were identified. These lines showed yield advantage under drought stress as well as irrigated conditions. MSM-36 showed better performance in the national coordinated trials conducted across India, which indicated that improved lines of Varalu expected to replace Varalu and may have an important role in sustaining rice production. The present study demonstrated the successful marker-assisted pyramiding strategy for introgression of genes/QTLs conferring biotic stress resistance and yield under abiotic stress in rice.

The calcium (Ca) sensor ROD1 (RESISTANCE OF RICE TO DISEASES1) is a master regulator of immunity in rice. By screening suppressors of mutants, we show that ROD1 governs immune homeostasis by surveilling the activation of a canonical immune pathway. Mutations in (), (), (), and () all abolish enhanced disease resistance of plants. OsTIR catalyzes the production of second messengers 2'-(5″-phosphoribosyl)-5'-adenosine monophosphate (pRib-AMP) and diphosphate (pRib-ADP), which trigger formation of an OsEDS1-OsPAD4-OsADR1 (EPA) immune complex. ROD1 interacts with OsTIR and inhibits its enzymatic activity, whereas mutation of leads to constitutive activation of the EPA complex. Thus, we unveil an immune network that fine-tunes immune homeostasis and multipathogen resistance in rice.

Tomato-rice rotation is prevalent in subtropical and tropical regions in China. This practice enhances crop productivity and the disease suppression property of soils against soil-borne plant pathogens. To explore the variations and dynamics of bacterial and fungal communities, bulk soil samples were collected during two consecutive years under a rotation system between tomato and rice originated from the year of 2010 in Hainan Island, and 16S rDNA and ITS amplicons were sequenced by Illumina MiSeq. The results demonstrated that potentially beneficial bacterial phyla Acidobacteria, Chloroflexi and genus Paenibacillus, as well as the fungal genus Mortierella were significantly enriched, while the potentially pathogenic fungal genus Fusarium was significantly decreased during the crop rotation. Measurements of soil physicochemical properties indicated that the soil acidification was improved. Redundancy analysis (RDA) revealed the correlation of the microbial community with soil pH and identified soil total phosphorus (TP) level as the highest determinant factor for both bacterial and fungal communities. This work provides a preliminary description of changes of the bacterial and fungal communities related to tomato-rice rotation in China and offered experimental evidences for exploring the effects of this agricultural practice on soil ecology.

为探究减氮条件下配施硅肥对水稻产量及病虫害的影响，本研究比较了氮肥常规用量和氮肥用量减少20%~40%条件下，配施一定量的硅肥对水稻产量及病虫害发生的影响。结果表明，与常规用量施氮（300 kg/hm2）相比，氮肥减少20%~40%条件下，配施硅肥提高了水稻的产量及经济效益，显著降低了卷叶螟的数量且提升了害虫天敌数量，并显著降低稻曲病发生率和病情指数，最终减轻水稻病虫害。

In order to explore the effects of applying silicon fertilizer on the yield and diseases and insect pests control of rice under reduced nitrogen fertilizer application, five different fertilization treatments were designed. The results showed that, compared with N300 treatment, the N240Si60 and N180Si60 treatments could improve the yield and economic benefits of rice. Under N240Si60 and N180Si60 treatments, the number of Cnaphalocrocis medinalis as well as the incidence and disease index of rice false smut were significantly decreased, moreover, the number of natural enemies was significantly increased.

The sheath blight disease of rice caused by Rhizoctonia solani is widely prevalent and one of the most destructive diseases, affecting rice cultivation and loss worldwide. In the present study, a set of twenty Bacillus isolates from saline soil of Uttar Pradesh were tested for their biocontrol activity against R. solani with the aim to obtain a potential strain for the control of sheath blight disease toward ecofriendly and sustainable agriculture. The results of dual-culture assay and scanning electron microscopic studies showed that the strain RH5 exhibited significant antagonistic activity (84.41%) against the fungal pathogen R. solani. On the basis of 16S rDNA sequencing analysis, the potential biocontrol strain RH5 was identified as Bacillus subtilis. Furthermore, the strain RH5 was characterized by different plant growth-promoting (PGP) activities and induction of defense-related enzymes in rice plants against R. solani. The strain RH5 posses various PGP attributes (indole acetic acid, siderophore, hydrogen cyanide production and phosphate, Zn, K solubility), hydrolytic enzymatic (chitinase, protease, cellulase, xylanase) activity, and presence of antimicrobial peptide biosynthetic genes (bacylisin, surfactin, and fengycin), which support the strain for efficient colonization of hyphae and its inhibition. Finally, the results of the greenhouse study confirmed that strain RH5 significantly increased plant growth and triggered resistance in rice plants through the production of defense-related antioxidant enzymes.© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Leaf blast is a significant global problem, severely affecting rice quality and yield, making swift, non-invasive detection crucial for effective field management. This study used hyperspectral remote sensing technology via an unmanned aerial vehicle to gather spectral data from rice crops. ANOVA and the Relief-F algorithm were used to identify spectral bands sensitive to the disease and developed a new vegetation index, the rice blast index (RBI). This RBI was compared with 30 established vegetation indexes, using correlation analysis and visual comparison to further shortlist six superior indexes, including RBI. These were evaluated using the K-nearest neighbor (KNN) and random forests (RF) classification models. RBI demonstrated superior detection accuracy for leaf blast in both the KNN model (95.0% overall accuracy and 93.8% kappa coefficient) and the RF model (95.1% overall accuracy and 92.5% kappa coefficient). This study highlights the significant potential of RBI as an effective tool for precise leaf blast detection, offering a powerful new mechanism and theoretical basis for enhanced disease management in rice cultivation.