摘要
全球气候变化、生境的特殊性及人为干扰等因素均能使湿地植物受到间歇或永久性的盐胁迫,进而影响到植物的存活、生长、分布和繁殖。在长期的适应进化过程中,湿地植物形成了多种适应盐胁迫的策略,主要有:1)生活史方面,植物可通过种子萌发时间的调整、种子休眠、胎生、繁殖方式的改变等逃避盐度的直接伤害;2)形态学方面,植物可通过生物量分配模式的调整、茎的老化、落叶及营养器官的肉质化等将多余的Na+隔离到代谢不活跃的茎中或将其排出体外;3)解剖学方面,植物可通过气孔下陷、发达的通气组织、增加细胞木栓层、角质层及栅栏组织的厚度等以维持植物正常的光合作用和呼吸作用;4)生理生化方面,植物可通过离子区隔化、拒盐、泌盐、选择性吸收、渗透调节、激素调节及抗氧化物酶的诱导等来维持细胞内正常的渗透压,清除胞内活性氧分子(ROS);5)分子水平方面,植物可通过多种与盐胁迫相关的基因来调控细胞内的多种代谢反应。在今后的研究中,Ca2+对脯氨酸合成的调控、变化盐度条件下的适应策略及根系功能的维持等方面仍需进一步加强。
Due to the effects of global climate change, special habitat, and human disturbance, wetland plants are usually suffered from intermittent or permanent salt stress, bringing in profound effects on their survival, growth, distribution, and reproduction. During the process of long-time adaptive evolution, wetland plants adopted a series of special strategies to acclimate to salt stress. The main strategies are ： 1 ） life history adjustment, e.g. , to adjust seed germination time, implement seed dormancy and viviparity, and change reproductive manner to escape from direct salt stress, 2） morphological adjustment, e. g. , to adjust biomass allocation pattern, age stem, defoliate, and carnify vegetative organs to isolate the redundant Na ^＋ to the inactive-metabolism shoots or exclude the Na ^＋ from tissues; 3） anatomic adjustment, e. g. , to sink stoma, develop aerenchyma, and thicken cuticle and phellogen to maintain normal photosynthesis and respiration; 4） physiological and biochemical adjustment, e.g. , to exclude and excrete salt, compartmentalize ions, adjust osmosis, do selective absorption, regulate hormones, and induce antioxidative enzymes to maintain the osmotic equilibrium and eliminate the active oxygen （ROS） in cell ; and 5 ） molecular level adjustment, e. g. , to start up many salt-induced genes to regulate the metabolic responses to salt stress. In the future, the studies on the Ca^2 ＋ -regulation of proline synthesis, adaptive strategies under conditions of variable salt contents, and functional mainte nance of root systems should be strengthened.
出处
《生态学杂志》
CAS
CSCD
北大核心
2009年第2期314-321,共8页
Chinese Journal of Ecology
基金
国家重点基础研究发展规划项目(2006CB403301)
国家自然科学基金项目(30770362)
世界自然基金会资助项目(CN8803-C2)
关键词
盐胁迫
湿地植物
生活史
离子区隔化
渗透调节
salt stress
wetland plant
life history
compartmentalization of ions
osmotic adjustment.
