RhMKK9, a rose MAP KINASE KINASE gene, is involved in rehydration-triggered ethylene production in rose gynoecia.
RhMKK9, a rose MAP KINASE KINASE gene, is involved in rehydration-triggered ethylene production in rose gynoecia.
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RhMKK9 是玫瑰 MAP KINASE 激酶基因，参与玫瑰雌蕊中补液触发的乙烯产生
DOI：
10.1186/s12870-017-0999-1
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发表时间：
2017-02-23
影响因子：
5.3
通讯作者：
Ma N
中科院分区：
文献类型：
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作者：
Chen J;Zhang Q;Wang Q;Feng M;Li Y;Meng Y;Zhang Y;Liu G;Ma Z;Wu H;Gao J;Ma N
背景开花是有花植物生活史中的一个重要过程，受多种内源和环境因素的影响。我们以前的工作表明，玫瑰（Rosa hybrida）花开放期间对脱水高度敏感，脱水后的水分恢复过程诱导雌蕊中迅速产生乙烯。此外，这种时间和空间特异性乙烯产生归因于雌核发育中玫瑰MAP激酶6-ACC合成酶1（RhMPK 6-RhACS 1）级联的短暂但强大的激活。然而，RhMPK 6-RhACS 1的上游组分是未知的，尽管RhMKK 9（MAP激酶9），一种玫瑰同系物，可以在体外激活RhMPK 6。在这项研究中，我们monitoredRhMKK 2/4/5/9的表达，潜在的上游激酶RhMPK 6，在玫瑰gynoclavirus在脱水和rehydration.ResultsWe发现只有RhMKK 9是快速和强烈诱导的再水化。沉默RhMKK 9显著降低再水化触发的乙烯产生。因此，在RhMKK 9基因沉默的花中，一些乙烯应答基因的表达下调。此外，我们还用Chop-PCR检测了RhMKK 9基因启动子和基因体的DNA甲基化水平。结果表明，再水化特异性地提高了RhMKK 9基因体的DNA甲基化水平，但却导致其启动子的低甲基化。结论RhMKK 9可能是RhMKK 9-RhMPK 6-RhACS 1级联反应的上游元件，参与了玫瑰雌蕊花水分恢复引发的乙烯产生，表观遗传DNA甲基化参与了再水化对RhMKK 9基因表达的调控。
BackgroundFlower opening is an important process in the life cycle of flowering plants and is influenced by various endogenous and environmental factors. Our previous work demonstrated that rose (Rosa hybrida) flowers are highly sensitive to dehydration during flower opening and the water recovery process after dehydration induced ethylene production rapidly in flower gynoecia. In addition, this temporal- and spatial-specific ethylene production is attributed to a transient but robust activation of the rose MAP KINASE6-ACC SYNTHASE1 (RhMPK6-RhACS1) cascade in gynoecia. However, the upstream component of RhMPK6-RhACS1 is unknown, although RhMKK9 (MAP KINASE KINASE9), a rose homologue ofArabidopsisMKK9, could activate RhMPK6 in vitro. In this study, we monitoredRhMKK2/4/5/9expression, the potential upstream kinase to RhMPK6, in rose gynoecia during dehydration and rehydration.ResultsWe found onlyRhMKK9was rapidly and strongly induced by rehydration. Silencing ofRhMKK9significantly decreased rehydration-triggered ethylene production. Consistently, the expression of several ethylene-responsive genes was down regulated in the petals ofRhMKK9-silenced flowers. Moreover, we detected the DNA methylation level in the promoter and gene body ofRhMKK9by Chop-PCR. The results showed that rehydration specifically elevated the DNA methylation level on theRhMKK9gene body, whereas it resulted in hypomethylation in its promoter.ConclusionsOur results showed that RhMKK9 possibly acts as the upstream component of the RhMKK9-RhMPK6-RhACS1 cascade and is responsible for water recovery-triggered ethylene production in rose gynoecia, and epigenetic DNA methylation is involved in the regulation ofRhMKK9expression by rehydration.