Biotic and abiotic stress down-regulate miR398 expression in Arabidopsis
Biotic and abiotic stress down-regulate miR398 expression in Arabidopsis
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DOI：
10.1007/s00425-009-0889-3
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发表时间：
2009-03-01
期刊：
影响因子：
4.3
通讯作者：
Sunkar, Ramanjulu
中科院分区：
文献类型：
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作者：
Jagadeeswaran, Guru;Saini, Ajay;Sunkar, Ramanjulu
MicroRNA 398靶向高等植物中的两种Cu/Zn超氧化物歧化酶（CSD 1和CSD 2）。先前的研究表明，在生长培养基中，在高Cu 2+或百草枯胁迫下，miR 398的表达降低，而在低Cu 2+或高蔗糖胁迫下，miR 398的表达增加。在这里，我们表明，额外的非生物胁迫，如臭氧和盐度也会影响miR 398水平。臭氧熏蒸降低了miR 398的水平，在缓解胁迫后逐渐恢复到正常水平。此外，miR 398水平降低拟南芥叶片浸润无毒菌株的假单胞菌pv.番茄Pst DC 3000（avrRpm 1或avrRpt 2），但不是强毒株Pst DC 3000。据我们所知，miR 398是第一个在生物胁迫下下调的miRNA（P.在臭氧、盐度和生物胁迫期间，CSD 1而不是CSD 2的mRNA水平与miR 398水平呈负相关，表明CSD 2的调节在不同胁迫期间并不严格受miR 398控制。总的来说，这项研究进一步建立了氧化应激和miR 398之间的联系。
MicroRNA398 targets two Cu/Zn superoxide dismutases (CSD1 and CSD2) in higher plants. Previous investigations revealed both decreased miR398 expression during high Cu2+ or paraquat stress and increased expression under low Cu2+ or high sucrose in the growth medium. Here, we show that additional abiotic stresses such as ozone and salinity also affect miR398 levels. Ozone fumigation decreased miR398 levels that were gradually restored to normal levels after relieved from the stress. Furthermore, miR398 levels decreased in Arabidopsis leaves infiltrated with avirulent strains of Pseudomonas syringae pv. tomato, Pst DC3000 (avrRpm1 or avrRpt2) but not the virulent strain Pst DC3000. To our knowledge, miR398 is the first miRNA shown to be down-regulated in response to biotic stress (P. syringae). CSD1, but not CSD2, mRNA levels were negatively correlated with miR398 levels during ozone, salinity and biotic stress, suggesting that CSD2 regulation is not strictly under miR398 control during diverse stresses. Overall, this study further establishes a link between oxidative stress and miR398 in Arabidopsis.