miR394 and LCR are involved in Arabidopsis salt and drought stress responses in an abscisic acid-dependent manner.
miR394 and LCR are involved in Arabidopsis salt and drought stress responses in an abscisic acid-dependent manner.
复制标题
miR394和LCR以脱落酸依赖性方式参与拟南芥盐和干旱胁迫反应
DOI：
10.1186/1471-2229-13-210
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发表时间：
2013-12-11
影响因子：
5.3
通讯作者：
Yang ZM
中科院分区：
文献类型：
--
作者：
Song JB;Gao S;Sun D;Li H;Shu XX;Yang ZM
研究背景MicroRNAs（miRNAs）是一类内源性非编码小分子RNA，能够与靶基因进行碱基配对，诱导其在植物中降解。miR 394 a/B是一种保守的小分子RNA，其靶基因LCR（LEAF CURLING RESPONSIVENESS）编码一个F-box蛋白（SKP 1-Cullin/CDC 53-F-box），但miR 394 a/B及其靶基因LCR是否参与调控植物对脱落酸（阿坝）和非生物胁迫的反应尚不清楚。相反，LCR表达被阿坝抑制。对LCR及其启动子（pLCR：：GUS）的分析表明，LCR在所有发育阶段都有表达，MIR 394 a/bover表达（35 S：：MIR 394 a/B）和LCR功能丧失（lcr）突变体对盐胁迫表现出超敏性，而LCR过表达（35 S：：m5 LCR）的植株表现出耐盐性。与野生型相比，35 S：：MIR 394 a/bandlcr植株对严重干旱胁迫具有高度耐受性，而35 S：：m5 LCR植株对水分亏缺敏感。MIR 394 a/流血的的过表达导致阿坝超敏反应和ABA相关表型，而35 S：：m5 LCR植物显示阿坝抗性表型。此外，35 S：：MIR 394 a/b植株比野生型和35 S：：m5 LCR植株积累了更高水平的ABA诱导的过氧化氢和超氧阴离子自由基。阿坝和胁迫响应基因ABI 3、ABI 4、ABI 5、ABF 3和ABF 4的表达在MIR 394 a/bover表达植物中上调，而在35 S：：m5 LCR植物中下调。结论miR 394沉默LCRmRNA是维持植物对非生物胁迫适应性反应的必要条件。盐和干旱反应的对比表型可能由miR 394和LCR之间的功能平衡介导。如果在非生物胁迫的情况下平衡被扰乱，则与胁迫反应相关的相同表型发生，导致阿坝敏感或不敏感的反应。因此，miR 394调节的LCR丰度可以允许植物微调它们对阿坝和非生物胁迫的响应。
BackgroundMicroRNAs (miRNAs) are a class of short, endogenous non-coding small RNAs that have ability to base pair with their target mRNAs to induce their degradation in plants. miR394a/b are conserved small RNAs and its target geneLCR(LEAF CURLING RESPONSIVENESS) encodes an F-box protein (SKP1-Cullin/CDC53-F-box) but whether miR394a/b and its target geneLCRare involved in regulation of plant response to abscisic acid (ABA) and abiotic stresses is unknown.ResultsMature miR394 and precursor miR394a/b are shown to be slightly induced by ABA. By contrast,LCRexpression is depressed by ABA. Analysis ofLCRand itspromoter(pLCR::GUS) revealed thatLCRis expressed at all development stages.MIR394a/bover-expression (35S::MIR394a/b) andlcr(LCRloss of function) mutant plants are hypersensitive to salt stress, butLCRover-expressing (35S::m5LCR) plants display the salt-tolerant phenotype. Both35S::MIR394a/bandlcrplants are highly tolerant to severe drought stress compared with wild-type, but35S::m5LCRplants are susceptible to water deficiency. Over-expression ofMIR394a/bled to ABA hypersensitivity and ABA-associated phenotypes, whereas35S::m5LCRplants show ABA resistance phenotypes. Moreover,35S::MIR394a/bplants accumulated higher levels of ABA-induced hydrogen peroxide and superoxide anion radicals than wild-type and35S::m5LCRplants. Expressions of ABA- and stress-responsive genes,ABI3,ABI4,ABI5,ABF3, andABF4are up-regulated inMIR394a/bover-expressing plants but down-regulated in35S::m5LCRplants. Over-expression ofMIR394ainabi4-1orabi5-1background resulted in loss of ABA-sensitivity in35S::MIR394aplants.ConclusionsThe silencing ofLCRmRNA by miR394 is essential to maintain a certain phenotype favorable for the adaptive response to abiotic stresses. The contrasting phenotypes of salt and drought responses may be mediated by a functional balance between miR394 andLCR. If the balance is perturbed in case of the abiotic stress, an identical phenotype related to the stress response occurs, resulting in either ABA sensitive or insensitive response. Thus, miR394-regulated LCR abundance may allow plants to fine-tune their responses to ABA and abiotic stress.