Exogenous silicon alleviates the adverse effects of cinnamic acid-induced autotoxicity stress on cucumber seedling growth

Abstract

Autotoxicity is a key factor that leads to obstacles in continuous cropping systems. Although Si is known to improve plant resistance to biotic and abiotic stresses, little is known about its role in regulating leaf water status, mineral nutrients, nitrogen metabolism, and root morphology of cucumber under autotoxicity stress. Here, we used cucumber seeds (Cucumis sativus L. cv. “Xinchun No. 4”) to evaluate how exogenous Si (1 mmol L−1) affected the leaf water status, mineral nutrient uptake, N metabolism-related enzyme activities, root morphology, and shoot growth of cucumber seedlings under 0.8 mmol L−1 CA-induced autotoxicity stress. We found that CA-induced autotoxicity significantly reduced the relative water content and water potential of leaves and increase their cell sap concentration. CA-induced stress also inhibited the absorption of major (N, P, K, Ca, Mg) and trace elements (Fe, Mn, Zn). However, exogenous Si significantly improved the leaf water status (relative water content and water potential) of cucumber leaves under CA-induced stress. Exogenous Si also promoted the absorption of mineral elements by seedlings under CA-induced stress and alleviated the CA-induced inhibition of N metabolism-related enzyme activities (including nitrate reductase, nitrite reductase, glutamine synthetase, glutamate synthase, glutamate dehydrogenase). Moreover, exogenous Si improved N uptake and utilization, promoted root morphogenesis, and increased the growth indexes of cucumber seedlings under CA-induced stress. Our findings have far-reaching implications for overcoming the obstacles to continuous cropping in cucumber cultivation.

Effects of Organic Acid Root Exudates of Malus hupehensis Rehd. Derived from Soil and Root Leaching Liquor from Orchards with Apple Replant Disease

“…Phloridzin lacks only one beta-D-glucopyranosyloxy group compared with Phloretin [ 40 ]. Replant stress inhibits the secretion of phloridzin by roots and promotes the secretion of phloridzin.…”

Response of Cucumis sativus to Neighbors in a Species-Specific Manner

“…It has been reported that flavonoids secreted by leguminous plants contribute to nitrogen fixation, and carboxylates to phosphorus acquisition [ 43 , 44 ]. Furthermore, allelopathic autotoxicity occurs due to some chemicals secreted by C. sativus itself, such as cinnamic acid [ 45 , 46 ]. In our study, no significant differences were found in all growth response variables in the G. max neighbor or intraspecific competition treatments compared with solitary growing conditions.…”

Untargeted metabolomics reveal rhizosphere metabolites mechanisms on continuous ramie cropping

“…Continuous cropping is the practice of planting the same crop or family on the same plot of land for many years. This can result in poor plant growth and development, smaller yellow leaves, increased disease, reduced crop quality, and lower yield ( Lyu et al., 2022 ). In recent decades, experts worldwide have begun to use crop science and ecology to study the barriers to continuous cropping at greater depths.…”