Effects of Soil Salinity on Sucrose Metabolism in Cotton Leaves

Abstract

This study investigated sucrose metabolism of the youngest fully expanded main-stem leaf (MSL) and the subtending leaf of cotton (Gossypium hirsutum L.) boll (LSCB) of salt-tolerant (CCRI-79) and salt-sensitive (Simian 3) cultivars and its relationship to boll weight under low, medium and high soil salinity stress in Dafeng, China, in 2013 and 2014. The results showed that with increased soil salinity, 1) both the chlorophyll content and net photosynthetic rate (Pn) decreased, while the internal CO2 concentration firstly declined, and then increased in the MSL and LSCB; 2) carbohydrate contents in the MSL reduced significantly, while sucrose and starch contents in the LSCB increased, as did the activities of sucrose phosphate synthase (SPS) and sucrose synthase (SuSy) in both the MSL and LSCB; 3) but invertase activity in both the MSL and LSCB did not change significantly. Our study also showed that the LSCB was more sensitive to soil salinity than was the MSL. Of the measured physiological indices, higher SPS activity, mainly controlled by sps3, may contribute to adaption of the LSCB to soil salinity stress because SPS is beneficial for efficiently sucrose synthesis, reduction of cellular osmotic potential and combined actions of Pn, and sucrose transformation rate and SPS may contribute to the reduction in boll weight under soil salinity stress.

Mechanistic Insight into Salt Tolerance of Acacia auriculiformis: The Importance of Ion Selectivity, Osmoprotection, Tissue Tolerance, and Na+ Exclusion

“…The reduction in Chl levels and consequent biomass loss were evident in other studies under salt stress, and the possible cause was attributed to the direct effects of accumulated Na + and ROS (Qin et al, 2010; Mostofa et al, 2015). In accordance with other reports, our results also implied that Chl a is more sensitive to salinity than Chl b (Li et al, 2008; Peng et al, 2016). Chl a is the most abundant and integral part of the light-harvesting complex, whereas Chl b as an accessory pigment acts indirectly in photosynthesis by transmitting photons to the Chl a (Chen, 2014; Gururani et al, 2015).…”

An Allelopathic Role for Garlic Root Exudates in the Regulation of Carbohydrate Metabolism in Cucumber in a Hydroponic Co-Culture System

“…In general, we speculate that the garlic-induced sugar accumulation in the leaves might be associated with an increase in the net activity of sucrose-synthetic enzymes (SPS, SS-s). Sucrose synthetase-cleavage (SS-c) decreased markedly, which suggests that salinity-mediated decreases in both might reflect the reducing capacity of assimilates in the source-to-sink translocation, ultimately flagging the sink viability [71]. Phenolic acid also caused the modification of the carbohydrate status.…”

Genome-wide association study reveals genetic variation and candidate genes of lint yield components under salt field conditions in cotton (Gossypium hirsutum L.)

“…Excavating elite alleles that can Cotton yield decreases under salt stress. The previous studies reported that SBW, LP and BNPP remarkably decreased under salt stress [46][47][48]. In present study, we selected four different field soil salt environments with two year replicates to investigate the lint yield components of cotton accessions.…”