黄瓜幼苗非结构性碳水化合物代谢对干旱胁迫与CO_2倍增的响应  

Responses of non-structural carbohydrate metabolism of cucumber seedlings to drought stress and doubled CO_2 concentration

作　　者：董彦红[1] 刘彬彬[2] 张旭[1] 刘学娜[1] 艾希珍[1,2] 李清明[1,2,3] 

机构地区：[1]山东农业大学园艺科学与工程学院,山东泰安271018 [2]作物生物学国家重点实验室,山东泰安271018 [3]农业部黄淮海设施农业工程科学观测实验站,山东泰安271018

出　　处：《应用生态学报》2015年第1期53-60,共8页Chinese Journal of Applied Ecology

基　　金：国家自然科学基金面上项目(31471918);中国博士后科学基金项目(201104646);国家"十二五"科技支撑计划项目(2012BAD11B01);山东省自然科学基金面上项目(ZR2013CM008);山东省高等学校科技计划项目(J14LF06);旱区作物逆境生物学国家重点实验室开放课题(CS-BAA2013005)资助

摘　　要：以‘津优1号’黄瓜水培幼苗为试材,采用裂区设计,主区设大气CO2浓度(约380μmol·mol-1)和倍增CO2浓度(760±20μmol·mol-1)2个CO2浓度处理,裂区设无干旱胁迫、中度干旱胁迫和重度干旱胁迫3个水分处理(以PEG 6000模拟根际干旱胁迫),研究了黄瓜幼苗非结构性碳水化合物代谢对干旱胁迫和CO2倍增的响应.结果表明:CO2倍增促进了黄瓜叶片中非结构性碳水化合物(葡萄糖、果糖、蔗糖、水苏糖)的积累,降低了渗透势,提高了黄瓜的耐旱性.在干旱胁迫处理过程中,叶片中蔗糖合成酶、可溶性酸性转化酶和碱性转化酶活性先上升后下降;根中可溶性酸性转化酶和碱性转化酶活性则逐渐上升,蔗糖磷酸合成酶活性先上升后下降.CO2倍增提高了蔗糖合成酶的活性而降低了蔗糖磷酸合成酶的活性,这两种酶和转化酶相互配合,促进了蔗糖的分解和抑制蔗糖合成,导致己糖积累,从而降低了细胞的渗透势,增强吸水能力.因此,CO2倍增能缓解干旱胁迫造成的不利影响,提高黄瓜的耐旱性,并且这种缓解效应在干旱胁迫严重时表现更为明显.The effects of doubled CO2 concentration on non-structural carbohydrate metabolism of cucumber （ Cucumis sativus L. cv. ＇ Jinyou No. 1＇ ） seedlings under drought stress were investigated. Split plot design was deployed, with two levels of CO2 concentrations （ambient CO2 concentration, 380 μmol·mol-1）, and doubled CO2 concentration, 760＋20 μmol·mol-1）） in the main plots, and three levels of water treatments （ control, moderate drought stress, and severe drought stress） simu- lated by PEG 6000 in the split-plots. The results showed that non-structural carbohydrates of cucum- ber leaves, including glucose, fructose, sucrose, and stachyose, increased with the doubling of CO2 concentration, which resulted in the decreased osmotic potential, improving the drought stress in cucumber seedlings. During the drought stress, sucrose synthase, soluble acid invertase and al- kaline invertase started with an increase, and followed with a decline in the leaves. In the root sys- tem, however, soluble acid invertase and alkaline invertase increased gradually throughout the whole process, whereas sucrose phosphate synthase firstly increased and then decreased. The treat- ment of doubled CO2 enhanced the activity of sucrose synthase, but decreased the activity of sucrosephosphate synthase. The synergistic action of the two enzymes and invertase accelerated the decom- position of sucrose and inhibited the synthesis of sucrose, leading to the accumulation of hexose, which lowered the cellular osmotic potential and enhanced the water uptake capacity. In conclusion, doubled CO2 concentration could alleviate the adverse effects of drought stress and improve the drought tolerance of cucumber seedlings. Such mitigating effect on cucumber was more significant under severe drought stress.

关 键 词：黄瓜 CO2倍增 干旱胁迫 非结构性碳水化合物 

分 类 号：S642.2[农业科学—蔬菜学]