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the plant journal：拟南芥同时增强生长和干旱胁迫抗性

已有 3789 次阅读 2018-10-6 15:59 |个人分类:每日摘要|系统分类:论文交流

A gene-stacking approach to overcome the trade-off between drought stress tolerance and growth in Arabidopsis

First author: Madoka Kudo; Affiliations: University of Tokyo (东京大学): Tokyo, Japan

Corresponding author: Kazuko Yamaguchi‐Shinozaki (篠崎和子)

The molecular breeding of drought stress-tolerant crops is imperative (必要的) for stable food and biomass production. However, a trade-off exists between plant growth and drought stress tolerance. Many drought stress-tolerant plants overexpressing stress-inducible genes, such as DEHYDRATION-RESPONSIVE ELEMENT-BINDING PROTEIN 1A (DREB1A), show severe growth retardation (生长迟缓). Here, we demonstrate that the growth of DREB1A-overexpressing Arabidopsis plants could be improved by coexpressing growth-enhancing genes whose expression is repressed under drought stress conditions. We used Arabidopsis GA REQUIRING 5 (GA5), which encodes a rate-limiting gibberellin biosynthetic enzyme, and PHYTOCHROME INTERACTING FACTOR 4(PIF4), which encodes a transcription factor regulating cell growth in response to light and temperature, for growth improvement. We observed an enhanced biomass and floral induction (成花诱导) in the GA5 DREB1A and PIF4 DREB1A double overexpressors compared with those in the DREB1A overexpressors. Although the GA5 DREB1A double overexpressors continued to show high levels of drought stress tolerance, the PIF4 DREB1A double overexpressors showed lower levels of stress tolerance than the DREB1A overexpressors due to repressed expression of DREB1A. A multiomics analysis of the GA5 DREB1A double overexpressors showed that the coexpression of GA5 and DREB1A additively affected primary metabolism (初生代谢), gene expression, and plant hormone profiles in the plants. These multidirectional analyses indicate that the inherent (固有的) trade-off between growth and drought stress tolerance in plants can be overcome by appropriate gene-stacking (基因叠加) approaches. Our study provides a basis for using genetic modification to improve the growth of drought stress-tolerant plants for the stable production of food and biomass.

对于作物来说，干旱胁迫抗性的分子育种是十分必要的，有利于稳定的食物来源及生物量产量。然而，在植物生长和干旱胁迫抗性之间存在一种权衡的关系。过表达DREB1A等胁迫诱导基因的具有干旱抗性的植株表现出严重的生长迟缓现象。本文揭示了在拟南芥中，可以通过协同表达干旱胁迫下收到抑制的生长增强基因来增强DREB1A过表达植株的生长。作者选择了拟南芥一个编码赤霉素生物合成限速酶基因GA5和一个编码响应于光和温度调控细胞生长的转录因子PIF4来增强植物的生长。作者在GA5 DREB1A和PIF4 DREB1A双过表达植株中均观察到了比DREB1A过表达植株更多的生物量和成花诱导。尽管GA5 DREB1A双过表达植株持续显示出高水平的干旱胁迫抗性，而PIF4 DREB1A双过表达植株由于DREB1A基因的表达相对于DREB1A过表达植株受到抑制，因而相比而言抗干旱的能力有所下降。通过对GA5 DREB1A双过表达植株多组学的分析，作者发现GA5和DREB1A基因加性影响植株的初生代谢、基因表达和植物激素。这些多方面的分析揭示了植物中固有的干旱胁迫抗性和生长之前的权衡可以通过适当的基因叠加的方法来克服。本文的研究为将来增强具有干旱胁迫抗性植株的生长以获取稳定食物产量和生物量提供了基因改造的基础。