Glycinebetaine-induced water-stress tolerance in codA-expressing transgenic indica rice is associated with up-regulation of several stress responsive genes
Glycinebetaine-induced water-stress tolerance in codA-expressing transgenic indica rice is associated with up-regulation of several stress responsive genes
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DOI：
10.1111/j.1467-7652.2009.00420.x
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发表时间：
2009-08-01
影响因子：
13.8
通讯作者：
Tyagi, Akhilesh K.
中科院分区：
文献类型：
--
作者：
Kathuria, Hitesh;Giri, Jitender;Tyagi, Akhilesh K.
P>水稻，甜菜碱（GB）非积累植物，对非生物胁迫高度敏感。转基因水稻叶绿体靶向胆碱氧化酶编码的codA基因从节杆菌球形已被评估的遗传转基因R5代和水分胁迫耐受性。在苗期、营养生长期和生殖生长期，转基因植株都能保持较高的光系统II活性，在水分胁迫下表现出比野生型植株更好的生理表现，如活性氧的解毒能力增强。转基因植株在长期水分胁迫下的存活率和农艺性状也优于野生型。胆碱氧化酶在一个步骤中将胆碱转化为GB和H2 O2。H_2O_2/GB有可能激活胁迫反应途径，制备抗逆转基因植株。为了验证这种可能性，已经进行了基于微阵列的转基因水稻转录组分析。它揭示了参与应激反应、信号转导、基因调节、激素信号传导和细胞代谢的许多基因的表达改变。总体而言，165个基因在转基因水稻中表现出超过两倍的上调，P值< 0.01。在这些基因中，已知至少有50个基因参与植物胁迫反应。对野生型植物外源施用H2 O2或GB也诱导这样的基因。我们的数据表明，GB的代谢工程是一个很有前途的策略，在作物中引入胁迫耐受性，可以赋予，部分，由H2 O2和/或GB诱导的应激反应基因。
P>Rice (Oryza sativa L.), a non-accumulator of glycinebetaine (GB), is highly susceptible to abiotic stress. Transgenic rice with chloroplast-targeted choline oxidase encoded by the codA gene from Arthrobacter globiformis has been evaluated for inheritance of transgene up to R5 generation and water-stress tolerance. During seedling, vegetative and reproductive stages, transgenic plants could maintain higher activity of photosystem II and they show better physiological performance, for example, enhanced detoxification of reactive oxygen species compared to wild-type plants under water-stress. Survival rate and agronomic performance of transgenic plants is also better than wild-type following prolonged water-stress. Choline oxidase converts choline into GB and H2O2 in a single step. It is possible that H2O2/GB might activate stress response pathways and prepare transgenic plants to mitigate stress. To check this possibility, microarray-based transcriptome analysis of transgenic rice has been done. It unravelled altered expression of many genes involved in stress responses, signal transduction, gene regulation, hormone signalling and cellular metabolism. Overall, 165 genes show more than two-fold up-regulation at P-value < 0.01 in transgenic rice. Out of these, at least 50 genes are known to be involved in plant stress response. Exogenous application of H2O2 or GB to wild-type plants also induces such genes. Our data show that metabolic engineering for GB is a promising strategy for introducing stress tolerance in crop plants and which could be imparted, in part, by H2O2- and/or GB-induced stress response genes.