Pérez Francisco Javier, Noriega Ximena, Rubio Sebastián
Laboratorio de Bioquimica Vegetal, Facultad de Ciencias, Universidad de Chile, Casilla 653, Las Palmeras, Ñuñoa 3425, Chile.
Antioxidants (Basel). 2021 May 29;10(6):873. doi: 10.3390/antiox10060873.
Changes in the level of hydrogen peroxide (HO) is a good indicator to monitor fluctuations in cellular metabolism and in the stress responses. In this study, the changes in HO content during bud endodormancy (ED) and budbreak were analysed in grapevine ( L.). The results showed a gradual increase in the HO content during the development of bud ED, which was mainly due to an increase in the activity of peroxidases (PODs). The maximum HO content reached in the grapevine buds coincided with the maximum depth of bud ED. In contrast, during budbreak, the HO content decreased. As the plant hormones cytokinin (CK) and auxin play an important role in budbreak and growth resumption in grapevine, the effect of exogenous applications of HO on the expression of genes involved in CK and auxin metabolism was analysed. The results showed that HO represses the expression of the CK biosynthesis genes and and induces the expression of the CK-inactivating gene , thus reducing potentially the CK content in the grapevine bud. On the other hand, HO induced the expression of the auxin biosynthesis genes and and of the auxin transporter gene , thus increasing potentially the auxin content and auxin transport in grapevine buds. In general, the results suggest that HO in grapevine buds is associated with the depth of ED and negatively regulates its budbreak.
过氧化氢（HO）水平的变化是监测细胞代谢波动和应激反应的良好指标。在本研究中，分析了葡萄（L.）芽内休眠（ED）和芽萌发过程中HO含量的变化。结果表明，在芽ED发育过程中，HO含量逐渐增加，这主要是由于过氧化物酶（PODs）活性增加所致。葡萄芽中达到的最大HO含量与芽ED的最大深度一致。相反，在芽萌发期间，HO含量下降。由于植物激素细胞分裂素（CK）和生长素在葡萄的芽萌发和生长恢复中起重要作用，分析了外源施用HO对参与CK和生长素代谢的基因表达的影响。结果表明，HO抑制CK生物合成基因和的表达，并诱导CK失活基因的表达，从而可能降低葡萄芽中的CK含量。另一方面，HO诱导生长素生物合成基因和以及生长素转运蛋白基因的表达，从而可能增加葡萄芽中的生长素含量和生长素运输。总体而言，结果表明葡萄芽中的HO与ED深度相关，并对其芽萌发起负调控作用。
