PeSHN1 regulates water-use efficiency and drought tolerance by modulating wax biosynthesis in poplar
PeSHN1 regulates water-use efficiency and drought tolerance by modulating wax biosynthesis in poplar
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PeSHN1 通过调节杨树蜡生物合成来调节水分利用效率和耐旱性
DOI：
10.1093/treephys/tpz033
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发表时间：
2019-08-01
期刊：
影响因子：
4
通讯作者：
Xia, Xinli
中科院分区：
文献类型：
--
作者：
Meng, Sen;Cao, Yang;Xia, Xinli
蜡质是一种疏水结构，为叶片提供有效的防水屏障，是防止水分流失的重要干旱适应性状。然而，有限的知识存在关于蜡生物合成的分子机制在树木。在这里，PeSHN 1，一个AP 2/乙烯反应因子转录因子，分离自速生白杨欧洲美洲杨cv。涅瓦河分身。为了研究PeSHN 1的潜在生物学功能，获得了过表达PeSHN 1的转基因84 K白杨（Populus alba x Populus glandulosa）植株。PeSHN 1过表达导致蒸腾作用减少，水分利用效率（WUE）增加和耐旱性增加。转基因白杨表现出增加的蜡质积累和改变的蜡质组成，主要是因为长链（>C30）脂肪酸，醛和烷烃的大量增加。基因表达分析表明，许多参与蜡生物合成的基因在PeSHN 1过表达植物中被诱导。此外，染色质免疫沉淀-PCR测定和双荧光素酶测定显示，这些基因中至少有一个LACS 2可能是PeSHN 1的靶基因。此外，PeSHN 1过表达植物在干旱胁迫条件下保持较高的光合活性和积累更多的生物量。综上所述，这些结果表明，PeSHN 1调节WUE和耐旱性在白杨通过调节蜡的生物合成和改变PeSHN 1的表达可能代表一种新的方法（改变叶片表面的蜡性状，以增加WUE）培育耐旱植物。
Wax, a hydrophobic structure that provides an effective waterproof barrier to the leaves, is an important drought adaptation trait for preventing water loss. However, limited knowledge exists regarding the molecular mechanisms underlying wax biosynthesis in trees. Here, PeSHN1, an AP2/ethylene response factor transcription factor, was isolated from a fast-growing poplar Populus x euramericana cv. 'Neva' clone. To study the potential biological functions of PeSHN1, transgenic 84K poplar (Populus alba x Populus glandulosa) plants overexpressing PeSHN1 were generated. PeSHN1 overexpression resulted in decreased transpiration, increased water-use efficiency (WUE) and increased drought tolerance. The transgenic poplar plants exhibited increased wax accumulation and altered wax composition, mainly because of a substantial increase in long-chain (>C30) fatty acids, aldehydes and alkanes. Gene expression analyses revealed that many genes involved in wax biosynthesis were induced in the PeSHN1 overexpression plants. In addition, chromatin immunoprecipitation-PCR assays and dual luciferase assays revealed that at least one of those genes, LACS2, is likely targeted by PeSHN1. Moreover, the PeSHN1 overexpression plants maintained higher photosynthetic activity and accumulated more biomass under drought stress conditions. Taken together, these results suggest that PeSHN1 regulates both WUE and drought tolerance in poplar by modulating wax biosynthesis and that altered PeSHN1 expression could represent a novel approach (altering the wax trait on leaf surfaces to increase WUE) for breeding drought-tolerant plants.