Yang Zhongyi,Gong Ruhai,Mimata Yoshiharu,Ye Shaosong,Ji Wei,Ye Wenxiu
A key tricarboxylic acid cycle metabolite, malate, accumulates in leaves during dehydration and induces stomatal closure by recruiting cytosolic Ca2+, activating a SLOW ANION CHANNEL-ASSOCIATED 1, and promoting reactive oxygen species. However, the effects of malate on stomatal opening and its underlying molecular mechanisms remain poorly understood. Our study revealed that, among TCA cycle metabolites, malate specifically inhibited light-induced stomatal opening in both grapevine and Arabidopsis. We demonstrated that SLAC1 was required for malate's inhibitory effects. The inhibition by malate was disrupted by Ca2+ signaling inhibitors. Additionally, malate signal was mediated by G-proteins, which regulate the production of second messengers. ROS production was abolished when G-proteins were inhibited. These findings show that malate efficiently maintains stomatal closure by not only inducing stomatal closure but also inhibiting stomatal opening. The inhibition of stomatal opening by malate is mediated through the activation of SLAC1 and the G-protein signaling cascade.
As biocompatible water-soluble nanomaterials, carbon dots (CDs) have attracted the interest of researchers in agricultural production. In this work, cerium-doped carbon dots (Ce-CDs) have been prepared as a water-soluble carbon nano-fertilizer using a one-pot hydrothermal method. The effects on lettuce yield and quality are investigated. The application of lower concentrations of Ce-CDs (50–150 mg L−1) all contributes to lettuce yield and quality enhancement. 100 mg L−1 of Ce-CDs demonstrates the most significant effect, increasing biomass by about 83.3% and promoting the accumulation of soluble sugars (87.5%) and soluble proteins (52.3%). Further investigation reveals that Ce-CDs can promote the electron transfer rate (33.35%), photosynthetic activity (30.28%), photoconversion efficiency (37.90%) and Rubisco activity (37.38%), and have a promoting effect on glutamine synthetase (GS, 3.10%) and glutamate synthase (GOGAT, 10.09%) activities. Regarding the net photosynthetic rate (54.99%), Ce-CDs elevate and induce stomatal opening and promote nutrient accumulation. This work not only evaluates the effects of rare earth-doped CDs as nano-fertilizers on plants but also provides strong technical support for the application of nano-fertilizers in practical production and life sciences.
危险品化学品经营许可证（带存储）