A NAC transcription factor, EjNAC1, affects lignification of loquat fruit by regulating lignin
A NAC transcription factor, EjNAC1, affects lignification of loquat fruit by regulating lignin
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DOI：
10.1016/j.postharvbio.2015.02.002
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发表时间：
2015-04-01
影响因子：
7
通讯作者：
Chen, Kunsong
中科院分区：
文献类型：
--
作者：
Xu, Qian;Wang, Wenqiu;Chen, Kunsong
木质素是次生细胞壁的重要组成部分，其含量影响植物产品的食品和纤维利用。枇杷是一种典型的木质素积累型果实。本研究分离了两个EjNAC基因，分别命名为EjNAC1和EjNAC2。EjNAC1和EjNAC2在酵母细胞中均具有转录活性。EjNAC1和EjNAC2在富含木质素的茎中的表达高于果肉。然而，只有EjNAC1在果实中受到低温诱导，而热处理（HT）则抑制了EjNAC1的表达，从而缓解了果实的木质化，而EjNAC2的表达与果实的木质化无关。进一步分析表明，EjNAC1可以反式激活枇杷和拟南芥中木质素合成途径基因的启动子。EjNAC1在烟草中的瞬时过表达导致了木质素的积累和内源木质素生物合成基因的诱导表达。总之，EjNAC1通过激活参与木质素生物合成的基因与果实木质化相关。(C)2015 Elsevier B.V.版权所有。
Lignin is an important component of secondary cell walls, and its content influences the utilization of plant products for food and fiber. Loquat is a typical fruit accumulating lignin during postharvest low temperature storage. In this research, two EjNAC genes were isolated and designated as EjNAC1 and EjNAC2. Both EjNAC1 and EjNAC2 had transcriptional activity in yeast cells. The expression of EjNAC1 and EjNAC2 in lignin-rich stems was higher than in pulp. However, only EjNAC1 was induced in fruit by low temperature and inhibited by heat treatment (HT), which can alleviate lignification, while EjNAC2 expression was not correlated with fruit lignification. Further analysis indicated that EjNAC1 could transactivate the gene promoters in loquat and Arabidopsis for genes in the lignin biosynthesis pathway. Transient over-expression of EjNAC1 in tobacco leaves resulted in accumulation of lignin and induction of expression of endogenous lignin biosynthesis genes. In conclusion, EjNAC1 was associated with fruit lignification by activating genes involved in lignin biosynthesis. (C) 2015 Elsevier B.V. All rights reserved.