甜菜保护酶系统对硼胁迫响应及其与内源激素相关性研究

研究不同硼素供应水平下， 硼对甜菜保护酶系统的影响规律以及保护酶系统与内源激素相关性， 丰富甜菜生理学理论。以甜菜单粒种 ‘HI0099’ 为试验材料， 在水培条件下， 设置 4个硼营养浓度， 对甜菜叶片保护酶系统以及内源激素含量进行测定。结果表明： 4种不同硼素处理的甜菜， 叶片中丙二醛(MDA)含量均随着生育进程有减少趋势， 而脯氨酸含量均呈增加趋势； 硼素胁迫处理时， 叶片 MDA含量以及脯氨酸含量增加。不同硼素处理下， 甜菜叶片超氧化物歧化酶(SOD)活性、 过氧化物酶(POD)活性表现为随生育进程逐渐升高趋势； 同一日期， 不同硼浓度表现为缺乏或者毒害胁迫下 SOD活性有升高的趋势， 并且随着甜菜生长， 硼胁迫情况下 SOD活性处理间差异有变小趋势； 在硼胁迫条件下， SOD活性与 ZT含量呈显著负相关(P＜0.05)， 与 GA₃呈极显著负相关(P＜0.01)。不同日期各硼素营养处理间过氧化氢酶(CAT)活性变化规律一致， 呈现先降低后升高的趋势。综合分析说明， 硼素胁迫引起膜脂过氧化， 甜菜叶片通过提高保护酶活性来防御硼毒害， 但其防御功能是有限的， 随着生育进程， 甜菜对硼胁迫防御功能达到临界值， 保护酶活性变化不再显著， 且甜菜植株在硼素胁迫下的生长发育受保护酶系统及内源激素间共同调控。

Effects of Boron Stress on Protective Enzyme System of Sugar Beet and Its Relationship with Endogenous Hormones

Objective]In order to support the theoretical basis of sugar beet production practice under boron application, the experiment was to study the nutrition absorbing rule in sugar beet plant under different boron levels.Method]Under water culture condition, sugar beet seed HI0099 was selected as experimental material. Four nutrition concentrations of boron were set: very deficiency, deficiency, moderate and excessive concentrations.Result]The results showed that MDA content of the leaves decreased and proline content increased. MDA concentration and proline content in leaves increased under different boron stress. With sugar beet growing, the activity of SOD and POD increased under different boron-treated. The SOD activity of sugar beet under low and excess boron stress tended to increase. With beet growing, the difference of SOD activity between three treatments decreased. Under boron stress, SOD activity and ZT content was significantly negatively correlated (P <0.05), with GA3 was a significant negative correlation (P <0.01). CAT activity presenting first and then decreased.Conclusion]Comprehensive analysis showed that boron stress caused by membrane lipid peroxidation, beet leaves by increasing protection to defense activity boron poison, but its defensive capabilities are limited, with the beet growing, boron deficiency defense reached a critical value, the protection activity change was no longer significant, and beet plant growth and development under the stress of boron by between protective enzyme system and common regulation of endogenous hormones.