Regulation of Growth and Physiological traits of Cucumber (Cucumis sativus L.) through various levels of 28-Homobrassinolide under salt stress conditions

Abstract

Brassinoids are plant steroidal hormones that are ubiquitous in the plant kingdom and regulate a wide range of physiological and stress responses. In a plastic tunnel pot bioassay experiment, three levels of 28-homobrassinolide (HBL) at 1, 3, and 5 μmol L −1 were tested for growth and physiological attributes of cucumber cultivars 'Jinyou 1' (salt-sensitive) and 'Changchun Mici' (salt-tolerant), grown at various salt stress conditions (60 and 120 mmol L −1). Cucumber plants of both cultivars subjected to salt stress exhibited reduced growth attributes and altered antioxidant enzymes at 60 and 120 mmol L −1. However, the deleterious effects of salt stress were partially improved by HBL. The foliar application of HBL enhanced shoot and root fresh and dry weight and chlorophyll content at 60 and 120 mmol L −1 NaCl stress in 'Jinyou 1' and 'Changchun Mici', respectively. Homobrassinolide application also altered the antioxidant enzyme levels by increasing super oxide dismutase and peroxidase levels and decreased malondialdehyde content under 60 and 120 mmol L −1 stress in both plant cultivars. Overall results showed that HBL could enhance growth attributes, chlorophyll content, and antioxidant enzymes for both of the cultivars under mild and high NaCl stress.

Insights into 28-homobrassinolide (HBR)-mediated redox homeostasis, AsA–GSH cycle, and methylglyoxal detoxification in soybean under drought-induced oxidative stress

“…In the present study, droughtaffected soybean seedlings exhibited growth retardation in terms of shoot length, FW, and DW, but these traits were improved by HBR application. A similar outcome was found in cucumber plants during salt stress, as reported by Ahmad et al (2017). The membrane protein complex was destabilized by drought stress resulting in the reduction of photosynthetic pigments (Hasanuzzaman et al 2014;Elkeilsh et al 2019).…”

The Protective Role of 28-Homobrassinolide and Glomus versiforme in Cucumber to Withstand Saline Stress

“…Currents results showed a negative effect of NaCl on leaf chlorophyll content and root activity of both cultivars, however, the cultivar Jinyou 1# revealed less tolerance to chlorophyll degradation and photosynthesis which was in accordance with Hayat et al, and Ahmad et al [7,39]. The decrease in chlorophyll content under salt stress might be due to overactivity of chlorophyllase, which damages chlorophyll content, and in turn, decreases photosynthetic activity and growth [37].…”

“…It has been reported that AMF, as compared to non-colonized plants, improved the growth and biomass of tomato [33,37], wheat, and pepper [34,38] under salt and water stress. Similarly, HBL has a positive effect on root and shoot growth and biomass in cucumber, Vigna radiata, and wheat under salt stress [6,7,39,40]. The increased growth attributes of cultivar CCMC might be due to its tolerant nature, enhanced nutrient acquisition through mycorrhizae [41] and positive effect on various osmolytes due to HBL [7], thereby increasing tolerance [42].…”

“…The experiment was replicated three times, and a total of 240 pots were used for a single cultivar. The selected treatments of NaCl were selected based on our previous research [39].…”

Enhanced Seedling Growth and Physiological Performances of Melia azedarach L. by Foliar Application of 24-Epibrassinolide under Salt Stress

“…Various physiological and agronomic techniques are commonly used to lessen the impact of saline stress [12]. The presence of salinity-tolerant halophytes and the variation in salt stress responses among glycophyte genotypes suggest the existence of diverse traits for improving plants' salt tolerance [13].…”