摘要
对不同季节白三叶(Trifolium repens)不同叶龄叶片(幼叶、中叶和老叶)抗氧化酶(SOD、POD和CAT)活力、渗透调节物(可溶性糖、可溶性蛋白和游离脯氨酸)含量、MDA含量和叶绿素含量进行分析,揭示白三叶不同叶龄叶片对不同季节温度适应的生理调控机理和白三叶叶片短寿在维护匍匐茎生长中的生态作用。结果表明:(1)冬季低温生出的幼叶MDA含量较低,而叶绿素a、POD和SOD活力、可溶性糖和脯氨酸含量均最高;夏季高温生出的幼叶MDA和叶绿素b含量较高,而POD和SOD活力、可溶性糖和脯氨酸含量较低。白三叶幼叶具有较强的生理调控可塑性以适应冬夏季温度。(2)不同季节幼叶成长过程中,其生理调控模式相近,随叶片长大成熟,叶绿素含量和SOD、POD、CAT活力及脯氨酸和可溶性糖含量均增高,而MDA含量降低。(3)不同季节老化叶片生理特征相同,叶片中可溶性糖和脯氨酸含量趋于增高,CAT活力及MDA含量均下降。研究表明,抗氧化酶和渗透调节物通过维护氧自由基代谢和水分代谢平衡而在幼叶适应不同季节温度、叶片快速生长中起重要保护作用。不同季节叶片抗氧化能力下降和持续积累的脯氨酸、可溶性糖抑制光合作用可能是叶片衰老和短寿的诱因。不同季节匍匐茎上叶片的短寿、快速衰老可使匍匐茎将能量物质分配给其顶部,促进匍匐茎顶部幼叶萌生和匍匐茎的延伸生长及种群的扩散,其在维护白三叶植株持续生存中具有重要的调控作用。
In this study, the activities of superoxide dismutase （SOD）, peroxide （POD） and catalse （CAT）, and the contents of soluble sugar, soluble protein, proline, malondialdehyde and chlorophyll in different aged leaves （young, middleaged, old） of white clover （Trifolium repens） were investigated in different seasons to understand how different aged leaves of white clover adapt to different seasonal temperatures in physiology and what ecological role of leaf senescence plays in maintaining stolon growth. The result showed that： （1） young leaves grown in winter had lower MDA content, and higher values in chlorophyll a content, SOD and POD activities, and soluble sugar and proline contents. However, young leaves grown in summer had higher MDA and chlorophyll b contents, but had lower SOD and POD activities and soluble sugar and proline contents. It is indicated that young leaves had higher physiological regulation plasticity in adaptation to different seasonal temperatures. （2） There existed a similar model of physiological regulation in the developing leaves grown in different seasons. When young leaves became mature, the contents of chlorophyll and soluble sugar and proline, and the activities of SOD and POD increased, while MDA content decreased. （3） Aging leaves grown in different seasons had same physiological characteristics. With the leaves becoming senescent, the soluble sugar and proline contents still increased, but the activities of SOD and CAT and content of MDA decreased. The antioxidant enzyme system and osmoregulation played an important role in physiological protection of young leaves to adapt different seasonal temperatures and in keeping their rapid growth by maintaining metabolic balance of oxygen free radicals and water metabolic balance. During leaf development, the antioxidant capacity decreased, and the proline and soluble sugar kept on accumulation, which was the reason inducing leaf senescence and short life. However, short life of leaves grown in different seasons would make more energy and matter being allocated to stolon top and promote leaf initiation, stolon elongation growth, and population expansion, which played an important physiological regulating role in maintaining growth of white clover in different seasons.
出处
《生态学杂志》
CAS
CSCD
北大核心
2016年第7期1713-1720,共8页
Chinese Journal of Ecology
基金
镇江市科技支撑计划项目(NY2013028)
院科技创新团队项目(2013td03)资助
关键词
季节
叶龄
白三叶
生理差异
叶片衰老机理
season
leaf age
Trifolium repens
physiological difference
leaf senescence physiology mechanism.
作者简介
张玥，女，1989年生，硕士研究生，研究方向为植物生理生态学。E-mail：sisi0508@vip．qq．com
通讯作者E-mail：Lianghuimin0218@126．com
