Double overexpression of DREB and PIF transcription factors improves drought stress tolerance and cell elongation in transgenic plants.
Double overexpression of DREB and PIF transcription factors improves drought stress tolerance and cell elongation in transgenic plants.
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DOI：
10.1111/pbi.12644
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发表时间：
2017-04
影响因子：
13.8
通讯作者：
Yamaguchi-Shinozaki K
中科院分区：
文献类型：
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作者：
Kudo M;Kidokoro S;Yoshida T;Mizoi J;Todaka D;Fernie AR;Shinozaki K;Yamaguchi-Shinozaki K
虽然已经产生了各种耐干旱胁迫的转基因植物，但其中许多植物表现出生长迟缓。为了提高植物的抗旱性和植物生长，我们应用了两个转录因子基因的基因堆积方法：脱水反应元件结合基因1A(DREB1A)和水稻光敏色素相互作用因子1(OsPIL1)。据报道，DREB1a的过表达提高了各种作物的抗旱性，尽管它也会导致严重的矮化表型。OsPIL1是拟南芥光敏色素相互作用因子4(PIF4)的水稻同系物，它通过激活细胞壁相关基因的表达来促进细胞伸长。我们发现，在光条件下，OsPIL1蛋白在拟南芥原生质体中比PIF4蛋白更稳定。转录激活分析表明，DREB1A和OsPIL1不会对彼此的转录活性产生负面影响。同时高表达OsPIL1和DREB1a的转基因植株表现出与DREB1A超表达的植株相似的抗旱性提高。此外，与DREB1A超表达基因相比，双过表达基因表现出促进下胚轴伸长和成花诱导的作用。代谢组学分析表明，糖和氨基酸等相容溶质在双过表达基因中积累，这与DREB1A过表达基因的观察结果相似。转录组分析表明，在双过表达基因中，非生物胁迫诱导的DREB1a下游基因和细胞伸长相关的OsPIL1下游基因的表达增加，这表明这两个转录因子在转基因植物中独立发挥功能，尽管需要权衡植物的生长和胁迫耐性。本研究为利用植物基因工程技术克服耐旱转基因植物的生长迟缓奠定了基础。
Although a variety of transgenic plants that are tolerant to drought stress have been generated, many of these plants show growth retardation. To improve drought tolerance and plant growth, we applied a gene‐stacking approach using two transcription factor genes: DEHYDRATION‐RESPONSIVE ELEMENT‐BINDING 1A (DREB1A) and rice PHYTOCHROME‐INTERACTING FACTOR‐LIKE 1 (OsPIL1). The overexpression of DREB1A has been reported to improve drought stress tolerance in various crops, although it also causes a severe dwarf phenotype. OsPIL1 is a rice homologue of Arabidopsis PHYTOCHROME‐INTERACTING FACTOR 4 (PIF4), and it enhances cell elongation by activating cell wall‐related gene expression. We found that the OsPIL1 protein was more stable than PIF4 under light conditions in Arabidopsis protoplasts. Transactivation analyses revealed that DREB1A and OsPIL1 did not negatively affect each other's transcriptional activities. The transgenic plants overexpressing both OsPIL1 and DREB1A showed the improved drought stress tolerance similar to that of DREB1A overexpressors. Furthermore, double overexpressors showed the enhanced hypocotyl elongation and floral induction compared with the DREB1A overexpressors. Metabolome analyses indicated that compatible solutes, such as sugars and amino acids, accumulated in the double overexpressors, which was similar to the observations of the DREB1A overexpressors. Transcriptome analyses showed an increased expression of abiotic stress‐inducible DREB1A downstream genes and cell elongation‐related OsPIL1 downstream genes in the double overexpressors, which suggests that these two transcription factors function independently in the transgenic plants despite the trade‐offs required to balance plant growth and stress tolerance. Our study provides a basis for plant genetic engineering designed to overcome growth retardation in drought‐tolerant transgenic plants.