Peng Jun, Liu Jingran, Zhang Lei, Luo Junyu, Dong Helin, Ma Yan, Zhao Xinhua, Chen Binglin, Sui Ning, Zhou Zhiguo, Meng Yali
Key Laboratory of Crop Physiology & Ecology in Southern China, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, China.
State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, China.
PLoS One. 2016 May 26;11(5):e0156241. doi: 10.1371/journal.pone.0156241. eCollection 2016.
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.
本研究于2013年和2014年在中国大丰，对耐盐品种（中棉所79）和盐敏感品种（泗棉3号）棉花（陆地棉）棉铃下的最幼嫩完全展开的主茎叶（MSL）及苞叶（LSCB）的蔗糖代谢及其与铃重的关系进行了调查，研究了低、中、高土壤盐分胁迫下的情况。结果表明，随着土壤盐分增加，1）MSL和LSCB中的叶绿素含量和净光合速率（Pn）均下降，而胞间CO2浓度先下降，后上升；2）MSL中的碳水化合物含量显著降低，而LSCB中的蔗糖和淀粉含量增加，MSL和LSCB中蔗糖磷酸合酶（SPS）和蔗糖合酶（SuSy）的活性也增加；3）但MSL和LSCB中的转化酶活性均无显著变化。我们的研究还表明，LSCB比MSL对土壤盐分更敏感。在所测定的生理指标中，主要由sps3控制的较高SPS活性可能有助于LSCB适应土壤盐分胁迫，因为SPS有利于高效合成蔗糖、降低细胞渗透势以及Pn的协同作用，并且蔗糖转化率和SPS可能导致土壤盐分胁迫下铃重降低。
