The issue of soil salinization is a global concern that significantly impairs crop productivity, quality, and distribution. Tonoplast Dicarboxylate Transporter (TDT) is a pivotal malic acid transporter localized on the vacuolar membrane, involving in maintaining intracellular pH homeostasis in plants. However, the molecular mechanisms and regulatory pathways underlying plant salt tolerance through TDT remain elusive. In this study, we cloned a gene encoding vacuolar membrane dicarboxylic acid transporter designated as SaTDT from the halophyte Spartina alterniflora. Subsequently, its role in regulating salt stress was investigated. The heterologous expression of SaTDT in Arabidopsis thaliana was observed to enhance the transgenic plants' tolerance to salt stress and alleviate the growth damage caused by this stress. The overexpression of SaTDT can simultaneously enhance plant photosynthetic efficiency by regulating the cellular contents of malic acid and citric acid, or by increasing the activity of MDH and PEPC enzymes. It also regulates and balances energy utilization during carbon assimilation under salt-stressed conditions, thereby establishing an energetic foundation for enhancing plant tolerance to stress. SaTDT also has the capacity to enhance the plant cells' ability in regulating antioxidant enzyme activity or osmotic accumulation, thereby playing a crucial role in maintaining intracellular redox homeostasis. In conclusion, our findings establish a foundation basis for elucidating the regulatory role of the SaTDT gene in S.alterniflora's adaptation to high-salinity habitats.
Main conclusion gamma-Aminobutyric acid alleviates acid-aluminum toxicity to roots associated with enhanced antioxidant metabolism as well as accumulation and transportation of citric and malic acids.AbstractAluminum (Al) toxicity has become the main limiting factor for crop growth and development in acidic soils and is further being aggravated worldwide due to continuous industrial pollution. The current study was designed to examine effects of GABA priming on alleviating acid-Al toxicity in terms of root growth, antioxidant defense, citrate and malate metabolisms, and extensive metabolites remodeling in roots under acidic conditions. Thirty-seven-day-old creeping bentgrass (Agrostis stolonifera) plants were used as test materials. Roots priming with or without 0.5 mM GABA for 3 days were cultivated in standard nutrient solution for 15 days as control or subjected to nutrient solution containing 5 mM AlCl36H2O for 15 days as acid-Al stress treatment. Roots were sampled for determinations of root characteristics, physiological and biochemical parameters, and metabolomics. GABA priming significantly alleviated acid-Al-induced root growth inhibition and oxidative damage, despite it promoted the accumulation of Al in roots. Analysis of metabolomics showed that GABA priming significantly increased accumulations of organic acids, amino acids, carbohydrates, and other metabolites in roots under acid-Al stress. In addition, GABA priming also significantly up-regulated key genes related to accumulation and transportation of malic and citric acids in roots under acid-Al stress. GABA-regulated metabolites participated in tricarboxylic acid cycle, GABA shunt, antioxidant defense system, and lipid metabolism, which played positive roles in reactive oxygen species scavenging, energy conversion, osmotic adjustment, and Al ion chelation in roots.
During (the Integrated Campaign for Aerosols, gases and Radiation Budget (ICARB) over India, I high-resolution airborne measurements of the attitude profiles of the mass concentrations (M-B) Of aerosol black carbon (BC) were made off Bhubaneswar (131311, 85.82 degrees E, 20.25 degrees N), over northwest B ay of Bengal, in the altitude region upto 3km. Such high-resolution measurements of altitude profiles of aerosols are done for the first time over India. The profiles showed a near-steady vertical I distribution of M-B modulated with two small peaks, one at 800 in and the other at similar to 2000 n(-1). High ) sonde (Vaisala) measurements around the same region resolution GPS (Global Positioning System onboard the research vessel Sagar Kanya (around the same time of the aircraft sortie) revealed two convectivelv well mixed layers one from ground to similar to 700m with an inversion at the top and the other extends from 1200 in to similar to 2000 in with a second inversion at similar to 2200 in and a Convectively stable region in the altitude range 700-1200 m. The observed peaks in the M-B profile are found to be associated with these temperature inversions. In addition, long-range transport from the Indo-Gangetic Plain (IGP) and deserts lying further to the west also influence the vertical profile of BC. Latitudinal variation of M-B Showed a remarkable land ocean contrast at the 500 in altitude (within the well mixed region) with remarkably lower values over oceans, suggesting the impact of strong In,sources over the mainland. However, above the ABL (at 1500m), the latitudinal variations were quite weak, and this appears to be resulting from the impact of long-range transport. Comparison of the altitude profiles of M-B over BoB off BBR, with those obtained during the earlier occasion over the inland stations of Hyderabad and Kanpur showed similarities above similar to 500m, with M-B remaining around a steady value of similar to 1 mu g m(-3). However, large differences are seen within the ABL. Even though the observed M-B values are not unusually high, their near constancy in the vertical column will have important implications to radiative forcing.