Overexpression of a NF-YC transcription factor from bermudagrass confers tolerance to drought and salinity in transgenic rice
Overexpression of a NF-YC transcription factor from bermudagrass confers tolerance to drought and salinity in transgenic rice
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狗牙根中 NF-YC 转录因子的过度表达赋予转基因水稻对干旱和盐度的耐受性
DOI：
10.1111/pbi.12151
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发表时间：
2015-05-01
影响因子：
13.8
通讯作者：
Guo, Zhenfei
中科院分区：
文献类型：
--
作者：
Chen, Miao;Zhao, Yujuan;Guo, Zhenfei
小麦黄花叶病毒（Wheat yellow mosaic virus，WYMV）在我国主要小麦产区迅速蔓延，造成严重的产量损失。由于它是由在土壤中长时间存活的真菌样生物多粘菌（Polymyxa graminis）传播的，因此很难通过传统的作物管理或杀真菌剂来消除。在商业栽培品种中也只有有限的抗性。本研究利用反义NIb 8基因（WYMV的NIb复制酶基因）和选择基因bar共转化获得了14个独立的转基因植株。田间试验表明，4个转基因亲本（N12、N13、N14和N15）和1个转基因后代（N12-1）对WYMV表现出高抗和持久抗性。通过PCR和后代除草剂抗性测试，4个抗性品系被证明已经分离并且仅含有NIb 8（不含bar）。N12-1对我国不同地区的WYMV分离物表现出广谱抗性。转基因小麦在感染土壤中生长后，组织打印和Western blot检测均未检测到WYMV。转基因小麦的籽粒产量比感病对照高10%左右。北方杂交和小分子RNA深度测序分析表明，转基因小麦植株中没有针对NIb 8基因的小分子干扰RNA的积累，表明转基因RNA沉默作为病毒来源的抗病性的一种常见机制，并不参与WYMV的抗性过程。核因子Y（Nuclear factor Y，NF-Y）是一种普遍存在的转录因子，由NF-YA、NF-YB和NF-YC三个亚基组成。从三倍体狗牙根（Cynodon dactylonxCynodon transvaalensis）中克隆了逆境应答基因NF-YC（Cdt-NF-YC 1），并研究了其在非生物胁迫耐受中的作用。Cdt-NF-YC 1转录本在所有营养组织中检测到，在根中观察到更高的水平。Cdt-NF-YC 1基因在叶片中的转录受脱水、盐胁迫、脱落酸（阿坝）、过氧化氢（H2 O2）和一氧化氮（NO）处理的诱导，但不受冷胁迫的影响。阿坝合成抑制剂和H2 O2或NO清除剂均能阻断Cdt-NF-YC 1在脱水和盐诱导下的转录，表明阿坝、H2 O2和NO参与了Cdt-NF-YC 1在脱水和盐诱导下的转录。Cdt-NF-YC 1的过表达提高了转基因水稻对干旱和盐胁迫的耐受性，并增加了对阿坝的敏感性。胁迫/阿坝响应基因（OsLEA 3、OsRAB 16 A、OsLIP 9和OsP 5CS 1）、阿坝合成和信号传导基因（OsNCED 3和OsABI 2）和ABA非依赖基因（OsDREB 1A、OsDREB 1B和OsDREB 2A）在转基因水稻中的转录水平显著高于野生型水稻。结果表明，Cdt-NF-YC 1是一个很好的候选基因，可以通过调节ABA依赖和ABA非依赖途径的基因调控来提高转基因水稻的耐旱性和耐盐性。
Wheat yellow mosaic virus (WYMV) has spread rapidly and causes serious yield losses in the major wheat-growing areas in China. Because it is vectored by the fungus-like organism Polymyxa graminis that survives for long periods in soil, it is difficult to eliminate by conventional crop management or fungicides. There is also only limited resistance in commercial cultivars. In this research, fourteen independent transgenic events were obtained by co-transformation with the antisense NIb8 gene (the NIb replicase of WYMV) and a selectable gene bar. Four original transgenic lines (N12, N13, N14 and N15) and an offspring line (N12-1) showed high and durable resistance to WYMV in the field. Four resistant lines were shown to have segregated and only contain NIb8 (without bar) by PCR and herbicide resistance testing in the later generations. Line N12-1 showed broad-spectrum resistance to WYMV isolates from different sites in China. After growing in the infested soil, WYMV could not be detected by tissue printing and Western blot assays of transgenic wheat. The grain yield of transgenic wheat was about 10% greater than the wild-type susceptible control. Northern blot and small RNA deep sequencing analyses showed that there was no accumulation of small interfering RNAs targeting the NIb8 gene in transgenic wheat plants, suggesting that transgene RNA silencing, a common mechanism of virus-derived disease resistance, is not involved in the process of WYMV resistance. This durable and broad-spectrum resistance to WYMV in transgenic wheat will be useful for alleviating the damage caused by WYMV.Nuclear factor Y (NF-Y) is a ubiquitous transcription factor formed by three distinct subunits, namely NF-YA, NF-YB and NF-YC. A stress-responsive cDNA of NF-YC (Cdt-NF-YC1) was isolated from triploid bermudagrass (Cynodon dactylonxCynodon transvaalensis), and its role in abiotic stress tolerance was investigated in this study. Cdt-NF-YC1 transcript was detected in all vegetative tissues with higher levels being observed in roots. Transcription of Cdt-NF-YC1 in leaves was induced by dehydration, salinity, and treatments with abscisic acid (ABA), hydrogen peroxide (H2O2) or nitric oxide (NO), but not altered by cold. The dehydration- or salt-induced transcription of Cdt-NF-YC1 was blocked by inhibitor of ABA synthesis and scavenger of H2O2 or NO, indicating that ABA, H2O2 and NO were involved in the dehydration- and salt-induced transcription of Cdt-NF-YC1. Overexpression of Cdt-NF-YC1 resulted in elevated tolerance to drought and salt stress and increased sensitivity to ABA in transgenic rice. Transcript levels of stress/ABA responsive genes (OsLEA3, OsRAB16A, OsLIP9 and OsP5CS1), ABA synthesis and signalling genes (OsNCED3 and OsABI2), and ABA-independent genes (OsDREB1A, OsDREB1B and OsDREB2A) were substantially higher in transgenic rice than in wild-type plants. The results suggested that that Cdt-NF-YC1 is a good candidate gene to increase drought and salinity tolerance in transgenic rice through modulating gene regulation in both ABA-dependent and ABA-independent pathways.