Disease resistance and abiotic stress tolerance in rice are inversely modulated by an abscisic acid-inducible mitogen-activated protein kinase
Disease resistance and abiotic stress tolerance in rice are inversely modulated by an abscisic acid-inducible mitogen-activated protein kinase
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DOI：
10.1105/tpc.008714
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发表时间：
2003-03-01
期刊：
影响因子：
11.6
通讯作者：
Yang, YN
中科院分区：
文献类型：
--
作者：
Xiong, LZ;Yang, YN
丝裂原活化蛋白激酶（MAPK）级联在真核生物中介导应激反应中起重要作用。然而，MAPKs在调节生物和非生物因子激活的防御途径相互作用中的作用知之甚少。在这项研究中，我们从水稻中分离出了一个应激响应的MAPK基因（OsMAPK5）并进行了功能表征。OsMAPK5是一个单拷贝基因，但可以产生至少两个差异剪接的转录本。OsMAPK5基因、其蛋白和激酶活性可被脱落酸以及各种生物（病原体感染）和非生物（创伤、干旱、盐和冷）胁迫诱导。为了确定其生物学功能，我们产生并分析了OsMAPK5过表达（使用花椰菜花叶病毒的35S启动子）或抑制（使用双链RNA干扰[dsRNAi]）的转基因水稻植株。有趣的是，OsMAPK5表达及其激酶活性的抑制导致病程相关（PR）基因如PR1和PR10在dsRNAi转基因植物中的组成型表达，并显著增强对真菌（稻瘟病菌）和细菌（颖壳伯克霍尔德氏菌）病原体的抗性。然而，这些相同的dsRNAi系在干旱、盐和冷耐受性方面具有显著降低。相比之下，过表达株系表现出增加的OsMAPK5激酶活性和增加的耐旱性，盐，和冷胁迫。这些结果有力地表明OsMAPK5可以正向调节耐旱性、耐盐性和耐冷性，而负向调节PR基因表达和广谱抗病性。
Mitogen-activated protein kinase (MAPK) cascades play an important role in mediating stress responses in eukaryotic organisms. However, little is known about the role of MAPKs in modulating the interaction of defense pathways activated by biotic and abiotic factors. In this study, we have isolated and functionally characterized a stress-responsive MAPK gene (OsMAPK5) from rice. OsMAPK5 is a single-copy gene but can generate at least two differentially spliced transcripts. The OsMAPK5 gene, its protein, and kinase activity were inducible by abscisic acid as well as various biotic (pathogen infection) and abiotic (wounding, drought, salt, and cold) stresses. To determine its biological function, we generated and analyzed transgenic rice plants with overexpression (using the 35S promoter of Cauliflower mosaic virus) or suppression (using double-stranded RNA interference [dsRNAi]) of OsMAPK5. Interestingly, suppression of OsMAPK5 expression and its kinase activity resulted in the constitutive expression of pathogenesis-related (PR) genes such as PR1 and PR10 in the dsRNAi transgenic plants and significantly enhanced resistance to fungal (Magnaporthe grisea) and bacterial (Burkholderia glumae) pathogens. However, these same dsRNAi lines had significant reductions in drought, salt, and cold tolerance. By contrast, overexpression lines exhibited increased OsMAPK5 kinase activity and increased tolerance to drought, salt, and cold stresses. These results strongly suggest that OsMAPK5 can positively regulate drought, salt, and cold tolerance and negatively modulate PR gene expression and broad-spectrum disease resistance.