Exogenous 2-(3,4-Dichlorophenoxy) triethylamine alleviates salinity stress in maize by enhancing photosynthetic capacity, improving water status and maintaining K+/Na+ homeostasis [post]

2020 unpublished
Soil salinity restricts plant growth and productivity. 2- (3,4-dichlorophenoxy) triethylamine (DCPTA) can alleviate salinity stress in plants. However, the mechanism of DCPTAmediated salinity tolerance has not been fully clarified. We aimed to investigate its role in enhancing photosynthetic capacity, improving water status, maintaining K + /Na + homeostasis and alleviating salinity stress in maize (Zea mays L.). Results: In present study, maize seedlings were grown in nutrient solutions with a
more » ... nt solutions with a combination of NaCl (0, 150 mM) and DCPTA (0, 20, 100, and 400 μM). And photosynthesis, water status, ion homeostasis and the expression of genes involved in ion uptake and transport were evaluated in the maize seedlings. The results demonstrated that DCPTA alleviated the growth inhibition of maize seedlings exposed to salinity stress by increasing the net photosynthetic rate (P n ) and the quantum efficiency of photosystem II (PSII) photochemistry. DCPTA improved the root hydraulic conductivity, which help maintained the water status. A relatively high K + concentration but a relatively low Na + concentration and the Na + /K + ratio were observed in the presence of DCPTA under salinity stress. Additionally, DCPTA altered the expression of four genes (ZmSOS1, ZmHKT1, ZmNHX1 and ZmSKOR) that encode membrane transport proteins responsible for K + /Na + homeostasis. Conclusions: DCPTA improved the salinity tolerance of maize may be associated with enhanced photosynthetic capacity, maintenance of water status and altered expression of genes involved in ion uptake and transport. Background Soil salinization is one of the most severe adverse environmental factors limiting agricultural development [1, 2] . Approximately 830 million hectares (ha) of land (approximately 20% of the cultivated land area worldwide) is impacted by soil salinization [3] [4] [5] , and an annual worldwide loss of US$12-27.3 billion occurs due to lost crop production [6] . It is expected that in 2050, the global population will surpass 9.1 billion, necessitating another 70% increase in food production to ensure food security [7] . Soil salinization will be the major obstacle in the way of achieving this goal [8] . Excess salt in the soil impedes plant growth and development by a multitude of mechanisms, designed the experiments. LJL, and SYZ gathered the data and analysed the results. SYZ, CFL, GLZ, CXC and CRQ helped to interpret the results and prepare the manuscript. WRG, SW, ZHW and WHL were in charge of manuscript revisions. All authors read and approved the final manuscript.
doi:10.21203/rs.3.rs-18017/v1 fatcat:quoimyws3fd7zihmixghfex5au