Effects of exogenous hydrogen sulphide on seed germination and seedling growth of cucumber (Cucumis sativus) under sodium bicarbonate stress

摘要

Soil salinity is a major limiting factor to agricultural land productivity worldwide, especially in arid and semi-arid regions. Hydrogen sulphide (H2S) plays an important role in a variety of responses against abiotic stresses. This study investigated the effects of exogenous NaHS, a H2S donor, on seed germination and seedling growth of cucumber (Cucumis sativus) under sodium bicarbonate (NaHCO3) stress. The results showed that NaHCO3 stress inhibited seed germination, reduced hypocotyl and radicle lengths, increased malondialdehyde (MDA) content, and decreased the soluble sugar content as well as alpha-amylase, beta-amylase, superoxide dismutase (SOD) and peroxidase (POD) activities in germinating seeds and seedlings of cucumber. On the other hand, exogenous NaHS treatment significantly increased hypocotyl and radicle lengths as well as the soluble sugar content. Moreover, exogenous NaHS treatment increased the activities of alpha-amylase, beta-amylase, SOD and POD and decreased the accumulation of MDA. Our findings strongly suggested that exogenous H2S effectively promotes cucumber seed germination and alleviates the toxic damage caused by NaHCO3 stress