《植物生理学报》 2014, 50(8): 1203-1208

冷胁迫下大麦幼苗根质膜水通道蛋白基因的表达

段瑞君^1,*, 熊辉岩², 且原真木³

青海大学¹生态环境工程学院, ²农牧学院, 西宁810016; ³冈山大学资源植物科学研究所, 日本仓敷710-0046

通信作者：段瑞君；E-mail: ruijunduan@163.com；Tel: 0971-5310086

摘　要：

植物质膜水通道蛋白(plasma membrane intrinsic proteins, PIPs)是位于细胞质膜上具有选择性、高效转运水分的一类膜内在蛋白, 参与植物生长发育的多个生理活动。本研究以大麦‘Haruna-nijo’为材料, 对水培幼苗进行4 ℃冷胁迫, 采用实时荧光定量PCR技术对胁迫期(4 ℃, 48 h)和温度恢复期(16 ℃, 48 h)两个过程的水通道蛋白PIPs基因表达进行了分析; 同期测定了根水导度(Lpr)、根长和苗高, 分析冷胁迫下大麦根PIPs基因的表达与水分生理的关系。结果表明: 大麦幼苗经4 ℃低温胁迫48 h后, 苗的生长明显受抑, 根的生长无显著变化; 温度恢复48 h后, 苗恢复生长, 根的生长无显著变化; 根水导度在胁迫期下降, 恢复期急剧升高, 均无显著差异。实时荧光定量PCR结果显示, 根中表达量最高的是HvPIP1;2和HvPIP1;3, 最低的是HvPIP1;1和HvPIP2;3; 冷处理后HvPIPs表达量与对照比较总体下降, 其中HvPIP1;2、HvPIP1;3、HvPIP1;4、HvPIP1;5、HvPIP2;1、HvPIP2;2明显下调。恢复后大多数HvPIPs表达量增加, HvPIP1;1、HvPIP1;2、HvPIP1;5、HvPIP2;3显著增加, HvPIP1;4、HvPIP2;5表达量降低, 但无显著差异。研究发现, 冷胁迫后大麦根HvPIPs的表达情况总体下调, 恢复生长大部分HvPIPs上调, 结合根水导度的变化, 推测大麦HvPIPs在抗冷反应中的作用复杂, 冷害的不同阶段HvPIPs对水分吸收所起的作用不同。

关键词：大麦; 水通道蛋白; 冷胁迫; 基因表达

收稿：2014-05-15   修定：2014-06-16

资助：国家自然科学基金(31160036)。

Expression of Root HvPIPs of Barley Seedling under Chilling Stress

DUAN Rui-Jun^1,*, XIONG Hui-Yan², Maki Katsuhara³

¹College of Eco-Environmental Engineering, ²College of Agriculture and Animal Husbandry, Qinghai University, Qinghai 810016, China; ³Institute of Plant Science and Resources, Okayama University, Kurashiki 710-0046, Japan

Corresponding author: DUAN Rui-Jun; E-mail: ruijunduan@163.com; Tel: 0971-5310086

Abstract:

The plant plasma membrane aquaporin (plasma membrane intrinsic proteins, PIPs) is a kind of membrane intrinsic proteins which has high selectivity and water transport. They play important roles in many physiological activities in plant growth and development. In this study, seedlings of barley variety ‘Haruna-nijo’ were treated with chilling stress. Expression of water channel protein PIPs of root in two processes which were stress period (4 ℃, 48 h) and recovery period (16 ℃, 48 h) were analyzed with quantitative real-time reverse transcriptase PCR (qRT-PCR). And root hydraulic conductivity (Lpr), root length and seedling height were analyzed at the same time. The results showed that: after 4 ℃ and 48 h stress, the growth of the barley seedlings was significantly inhibited, but root growth was no significant changed; after 16 ℃, 48 h recovery, shoot height of stressed-seedling caught up that of control seedlings and root growth did not change significantly; root hydraulic conductivity decreased in the period of chilling stress and increased rapidly in recovery period but there were no significant difference. The results of qRT-PCR showed: the highest expression were HvPIP1;2 and HvPIP1;3, the lowest expression were HvPIP1;1 and HvPIP2;3. Compared with the control group, HvPIPs expression were decreased in all after cold treatment, in which HvPIP1;2, HvPIP1;3, HvPIP1;4, HvPIP1;5, HvPIP2;1, HvPIP2;2 were down-regulated significantly. In recovery period, most of HvPIPs expression were increased, espeacally HvPIP1;1, HvPIP1;2, HvPIP1;5, HvPIP2;3 were up-regulated significantly, but HvPIP1;4, HvPIP2;5 were down-regulated. This study found that HvPIPs expressions of barley root were down-regulated overall in chilling stress and in recovery growth most HvPIPs were up-regulated. Combined with changes of root hydraulic conductivity and plant growth, the role of barley HvPIPs in chilling resistance reaction speculated that HvPIPs effected water absorption were different in different stages.

Key words: barley; aquaporins; chilling stress; gene expression