Cui Weiti, Zhu Dan, Shen Wenbiao, Mei Yudong, Hu Dekun, Shi Yujian, Ren Yong, Shen Wei, Gu Quan, Xu Daokun, Huang Liqin
Laboratory Center of Life Sciences, College of Life Sciences, Nanjing Agricultural UniversityNanjing, China.
College of Sciences, Nanjing Agricultural UniversityNanjing, China.
Front Plant Sci. 2017 Aug 18;8:1445. doi: 10.3389/fpls.2017.01445. eCollection 2017.
Although previous results showed that -cyclodextrin-hemin complex (-CDH) could induce tomato lateral root (LR) formation, the corresponding downstream messengers are still not fully understood. In this report, similar to the inducing effects of exogenously applied hydrogen peroxide (HO), we discovered that -CDH elicited transcript upregulation, endogenous HO accumulation, and thereafter tomato LR development. Above responses were sensitive to dimethylthiourea (DMTU) and ascorbic acid (AsA), two membrane-permeable scavengers of HO, showing that accumulation of HO and LR formation were significantly blocked. The test with diphenyleneiodonium (DPI; the inhibitor of NADPH oxidase) revealed that HO mainly produced by NADPH oxidase, might be involved in LR formation triggered by -CDH. qPCR combined with pharmacological and anatomical analyses showed that -CDH-modulated several marker genes responsible for LR formation, such as , and (four cell cycle regulatory genes), and (two auxin signaling genes), (an auxin influx carrier), (encoding a member of the Aux/IAA protein family), and (two auxin efflux carriers), , and genes (two reactive oxygen species-associated genes and one LR formation-related gene), were causally related to above HO signaling. Particularly, representative proteins related to HO metabolism and lateral rooting, were specifically induced in -CDH-treated tomato seedlings. Overall, the results clearly suggested a vital role of HO in the -CDH-induced tomato LR formation, and -CDH-elicited HO-related target proteins responsible for LR formation might be, at least partially, regulated at transcriptional and translational levels.
尽管先前的研究结果表明，β-环糊精-血红素复合物（β-CDH）能够诱导番茄侧根（LR）的形成，但其相应的下游信使仍未完全明确。在本报告中，与外源施加过氧化氢（H₂O₂）的诱导效应相似，我们发现β-CDH能够引发相关转录本上调、内源性H₂O₂积累，进而促进番茄侧根发育。上述反应对HO的两种膜通透性清除剂二甲基硫脲（DMTU）和抗坏血酸（AsA）敏感，表明HO的积累和侧根形成均被显著阻断。用二苯基碘鎓（DPI；NADPH氧化酶抑制剂）进行的试验表明，主要由NADPH氧化酶产生的HO可能参与了β-CDH引发的侧根形成过程。定量聚合酶链反应（qPCR）结合药理学和解剖学分析表明，β-CDH调控了多个负责侧根形成的标记基因，如（四个细胞周期调控基因）、和（两个生长素信号基因）、（一个生长素流入载体）、（编码Aux/IAA蛋白家族成员）、和（两个生长素流出载体）、、和基因（两个活性氧相关基因和一个侧根形成相关基因），这些基因与上述HO信号传导存在因果关系。特别地，与HO代谢和侧根发生相关的代表性蛋白质在β-CDH处理的番茄幼苗中被特异性诱导。总体而言，结果清楚地表明HO在β-CDH诱导的番茄侧根形成中起着至关重要的作用，并且β-CDH引发的与侧根形成相关HO靶蛋白可能至少部分在转录和翻译水平上受到调控。
