Importance of hydrogen sulfide as the molecular basis of heterosis in hybrid Brassica napus: A case study in salinity response
Importance of hydrogen sulfide as the molecular basis of heterosis in hybrid Brassica napus: A case study in salinity response
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DOI：
10.1016/j.envexpbot.2021.104693
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发表时间：
2021-11-11
影响因子：
5.7
通讯作者：
Shen, Wenbiao
中科院分区：
文献类型：
--
作者：
Cheng, Pengfei;Zhang, Yihua;Shen, Wenbiao
杂种优势或杂种优势是杂合子在一个或多个性状上优于两个亲本的现象，甚至是对逆境的反应。然而，相关的分子机制仍未完全阐明。在本文中，我们研究了哺乳动物和植物中普遍存在的信号分子硫化氢是否参与了杂种优势。在盐分胁迫下，甘蓝型油菜亲本(NJ4375和MB1894)比杂交种(F1，NJ4375×MB1894)对盐分的反应更为敏感，表现为对茎长、根长、根鲜重和叶绿素含量的降低有明显的促进作用。进一步观察到，在盐分胁迫下，杂交种的内源H_2S合成的增加比两个亲本更为明显，这表明内源H_2S的重要作用。其生物合成抑制剂(PAG)和清除剂(HT)对内源H_2S的清除可以不同程度地消除杂交种的耐盐性。随后的实验表明，该杂交种可以通过调节钠和钾转运蛋白来维持离子动态平衡，这一点通过调节NHX1、SOS2、AKT1和Hak5转录本得到了证实。与NJ4375和MB1894相比，杂交植株的脯氨酸含量显著增加，膜脂过氧化作用明显减轻。杂交种的上述反应对内源H_2S合成的抑制或其清除反应敏感。综上所述，我们的研究结果清楚地证明了杂交种的耐盐优势可能与内源H_2S信号密切相关。
Heterosis or hybrid vigor is a phenomenon that a heterozygote is superior to two parental lines in one or more traits, or even responses against stresses. However, related molecular mechanism is still not fully elucidated. In this paper, we investigated whether hydrogen sulfide (H2S), a universal signaling molecule in both mammals and plants, participates in heterosis. When upon salinity stress, two parents of Brassica napus (NJ4375 and MB1894) were more sensitive to salinity compared to the hybrid (F1, NJ4375xMB1894), evaluated by the improving effects on the reduction in shoot length, root length, fresh weight of root parts, and chlorophyll content. It was further observed that the increased endogenous H2S synthesis was more pronounced in the hybrid than those of two parental lines when stressed with salinity, suggesting the important roles of endogenous H2S. The removal of endogenous H2S by its biosynthesis inhibitor (PAG) and scavenger (HT) could differentially abolish the salinity tolerance observed in the hybrid. Subsequent experiments showed that the hybrid could maintain ion homeostasis by regulating the sodium and potassium transporters, which was confirmed by modulating NHX1, SOS2, AKT1 and HAK5 transcripts. Proline content was also significantly increased and lipid peroxidation was obviously alleviated in the hybrid plants compared to those in both NJ4375 and MB1894. Above responses in hybrid were sensitive to the inhibition of endogenous H2S synthesis or its scavenging. Overall, our results clearly provided the evidence that salt-tolerant heterosis of hybrid might be closely associated with endogenous H2S signaling.