淹水胁迫对小白菜幼苗根系生长、生理及凯氏带的影响

Effects of flooding stress on growth, physiology and casparian strip of roots in Chinese cabbage seedlings

采用双因素随机区组设计研究了淹水胁迫对小白菜幼苗根系生长、生理及凯氏带的影响。结果表明:淹水5、10和15d时,虽然4个小白菜品种根系的生长均受到淹水胁迫的抑制,但都未死亡,说明它们皆具有一定的淹水胁迫耐性。在淹水10和15d时,4个小白菜品种根系的LDH和PAL活性均显著高于对照,且在根的成熟部位(距根的最先端3cm处)内皮层均形成了凯氏带,说明它们的根系不仅增强无氧呼吸来抵抗淹水胁迫,还提高PAL活性形成凯氏带来适应淹水胁迫。恢复5d时,4个小白菜品种的根系ADH、LDH、PAL活性和根系活力比淹水15d时均有所恢复,根的幼嫩部位(距根的最先端1cm处)凯氏带消失。

The effects of flooding stress on growth,physiology and casparian strip of roots in Chinese cabbage seedlings were studied by using two-factor randomized block design.The results showed that at 5,10 and 15 days of flooding stress,although the root growth of the four Chinese cabbage cultivars was inhibited,they did not die,indicating that they all had a certain degree of tolerance to flooding stress.The LDH and PAL activities in roots of four Chinese cabbage cultivars were significantly higher than control at 10 and 15 days after flooding stress,and the endodermis of the mature parts of the roots (3 cm from the root tip) all formed the casparian strip.This indicated that the roots of them not only enhanced anaerobic respiration to resist flooding stress but also enhanced PAL activity to form casparian strip for adapting to flooding stress.Compared with 15 days flooding stress,ADH,LDH,PAL and root activities of four Chinese cabbage cultivars were restored after 5-day recovery,and the casparian strip disappeared at the tender part of the root (1 cm from the root tip).