Improvement of water use efficiency in rice by expression of HARDY, an Arabidopsis drought and salt tolerance gene
Improvement of water use efficiency in rice by expression of HARDY, an Arabidopsis drought and salt tolerance gene
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DOI：
10.1073/pnas.0707294104
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发表时间：
2007-09-25
影响因子：
11.1
通讯作者：
Pereira, Andy
中科院分区：
文献类型：
--
作者：
Karaba, Aarati;Dixit, Shital;Pereira, Andy
淡水是一种有限且日益减少的全球资源；因此，需要对稻米等需水较高的粮食作物或生产可持续能源生物质的粮食作物进行高效用水。我们在这里表明，在水稻中表达拟南芥Hardy(HRD)基因可以通过增强光合作用同化和减少蒸腾作用来提高水分利用效率，即生物量生产与水分利用的比率。这些耐旱、低耗水的水稻植株在良好的灌溉条件下表现出较高的地上部生物量，在干旱胁迫下表现出适应性的根部生物量增加。HRD基因是一种AP2/ERF类转录因子，由功能增强的拟南芥突变体hrd-D鉴定，其根具有增强的强度、分枝和皮层细胞，表现出抗旱性和耐盐性，并伴随着非生物胁迫相关基因的表达增强。在拟南芥中过表达HRD会产生更厚的叶片和更多的含叶绿体的叶肉细胞，而在水稻中，叶片生物量和束鞘细胞的增加可能有助于光合作用同化和效率的提高。结果表明，从模式植物拟南芥中发现的一个基因应用于提高作物水稻的水分利用效率与抗旱性是一致的。
Freshwater is a limited and dwindling global resource; therefore, efficient water use is required for food crops that have high water demands, such as rice, or for the production of sustainable energy biomass. We show here that expression of the Arabidopsis HARDY (HRD) gene in rice improves water use efficiency, the ratio of biomass produced to the water used, by enhancing photosynthetic assimilation and reducing transpiration. These drought-tolerant, low-water-consuming rice plants exhibit increased shoot biomass under well irrigated conditions and an adaptive increase in root biomass under drought stress. The HRD gene, an AP2/ERF-like transcription factor, identified by a gain-of-function Arabidopsis mutant hrd-D having roots with enhanced strength, branching, and cortical cells, exhibits drought resistance and salt tolerance, accompanied by an enhancement in the expression of abiotic stress associated genes. HRD overexpression in Arabidopsis produces thicker leaves with more chloroplast-bearing mesophyll cells, and in rice, there is an increase in leaf biomass and bundle sheath cells that probably contributes to the enhanced photosynthesis assimilation and efficiency. The results exemplify application of a gene identified from the model plant Arabidopsis for the improvement of water use efficiency coincident with drought resistance in the crop plant rice.