| 伯克氏菌Y4对水稻幼苗镉损伤和镉吸收的影响 |
| 摘要点击 2444 全文点击 1023 投稿时间：2021-08-05 修订日期：2021-09-23 |
| 查看HTML全文
查看全文 查看/发表评论 下载PDF阅读器 |
| 中文关键词 伯克氏菌Y4 水稻 镉(Cd) 氧化应激 Cd2+流速 |
| 英文关键词 Burkholderia sp. Y4 rice cadmium(Cd) oxidative stress Cd2+ flux rate |
| 作者 | 单位 | E-mail | | 张雅荟 | 农业农村部环境保护科研监测所, 天津 300191
天津城建大学环境与市政工程学院, 天津市水质科学与技术重点实验室, 天津 300384 | 592534837@qq.com | | 刘月敏 | 天津城建大学环境与市政工程学院, 天津市水质科学与技术重点实验室, 天津 300384 | lyuemn@126.com | | 王常荣 | 农业农村部环境保护科研监测所, 天津 300191 | wangchangrong109@163.com | | 刘雅萍 | 农业农村部环境保护科研监测所, 天津 300191
天津城建大学环境与市政工程学院, 天津市水质科学与技术重点实验室, 天津 300384 | | | 庞杰 | 农业农村部环境保护科研监测所, 天津 300191
天津城建大学环境与市政工程学院, 天津市水质科学与技术重点实验室, 天津 300384 | | | 黄永春 | 农业农村部环境保护科研监测所, 天津 300191 | | | 刘仲齐 | 农业农村部环境保护科研监测所, 天津 300191 | | | 张长波 | 农业农村部环境保护科研监测所, 天津 300191 | |
|
| 中文摘要 |
| 为探明伯克氏菌Y4（Burkholderia sp.Y4）对镉（Cd）胁迫下水稻幼苗的生长和Cd吸收积累的影响及其作用机制，以水稻低Cd积累品种湘早籼24（X24）和高Cd积累品种T优705（T705）为材料，通过水稻种子萌发和幼苗试验，利用非损伤微测技术和原子吸收等检测方法，研究外源施加伯克氏菌Y4对Cd胁迫下水稻生长和毒性损伤的影响及其抑制水稻Cd吸收积累的作用机制.结果表明，伯克氏菌Y4可以缓解Cd对水稻生长的抑制作用，使种子发芽势提高13.8%，此外，接种菌株Y4后7 d，水稻幼根和幼芽长度分别增长83.3%和12.2%，干重分别增加56.8%和12.5%，而接种菌株Y4后10 d，水稻幼根和幼芽长度分别增长28.6%和20.0%，干重分别增加113.2%和46.0%.深入研究发现，施加菌株Y4缓解了Cd胁迫下水稻的氧化应激损伤，显著降低了幼苗地上部及根系中氧化损伤产物丙二醛（MDA）的水平，降幅分别达到21.5%和16.9%；同时，Cd胁迫下水稻抗氧化酶活性的变化也在菌株Y4的作用下得到缓解，幼苗根系中超氧化物歧化酶（SOD）和过氧化氢酶（CAT）的活性水平恢复至与无Cd空白对照组无显著差异，而幼苗地上部中的酶活变化幅度也分别由176.9%和74.8%降低至53.3%和21.5%.另一方面，伯克氏菌Y4还能够抑制不同Cd积累型水稻品种幼苗对Cd的吸收，外源施加菌株Y4显著降低了水稻幼苗地上部及根系中的Cd含量，使高Cd积累品种T705地上部及根系中Cd含量分别下降79.2%和62.7%，而在低Cd积累品种X24中的降幅分别为57.3%和24.1%.深入研究发现，根施伯克氏菌Y4可使水稻幼苗根系表面形成黄色根膜，同时降低了根伸长区的Cd2+离子流速.高Cd积累品种T705对Cd2+的吸收流速显著高于低Cd积累品种X24，外源施加菌株Y4使3 d苗龄T705和X24对Cd2+的吸收流速分别下降36.0%和35.0%，而10 d苗龄T705和X24对Cd2+的吸收流速则分别下降44.6%和24.9%.由此可见，伯克氏菌Y4通过缓解Cd胁迫造成的氧化应激反应，能够降低Cd对水稻生长的抑制作用和毒性损伤，此外，菌株Y4还能够改变水稻根膜并有效降低不同品种水稻根伸长区对Cd2+的吸收速率和根Cd积累量，进而抑制Cd向地上部的转运积累，为伯克氏菌Y4作为水稻降Cd促生菌剂的应用提供了理论依据和数据支持. |
| 英文摘要 |
| In order to investigate the effects of Burkholderia sp. Y4 on rice seedlings under cadmium (Cd) stress, seed germination and vermiculite culture experiments were conducted using low Cd-accumulation xiangzaoxian 24 (X24) and high Cd-accumulation Tyou 705 (T705) varieties. The effects of Burkholderia sp. Y4 on rice growth, oxidative damage caused by Cd, and Cd accumulation were studied. Additionally, the Cd2+ flux rates in the elongation zone of rice roots under Burkholderia sp. Y4 application were detected using non-invasive micro-test technology. Burkholderia sp. Y4 alleviated the inhibition effect of Cd on rice seed germination by 13.8%. After inoculation with Burkholderia sp. Y4 for 7 d, the length of rice roots and buds increased by 83.3% and 12.2%, and their dry weight increased by 56.8% and 12.5%, respectively; those in the 10 d Y4 inoculation group increased by 28.6% and 20.0% in length and by 113.2% and 46.0% in dry weight, respectively. Burkholderia sp. Y4 inoculation also alleviated rice oxidative stress damage caused by Cd. The application of strain Y4 significantly reduced the content of the oxidative damage product malondialdehyde (MDA) in the shoots and roots of rice seedlings by 21.5% and 16.9%, respectively. Under Burkholderia sp. Y4 inoculation, the significant changes in antioxidant enzyme SOD and CAT activities caused by Cd stress disappeared in rice roots; those in shoots also decreased from 176.9% and 74.8% to 53.3% and 21.5%, respectively. Conversely, Burkholderia sp. Y4 inhibited Cd uptake by rice seedlings with different genotypes, including the low Cd-accumulation variety X24 and high Cd-accumulation variety T705. The root application of strain Y4 significantly reduced Cd accumulation in the shoots and roots of rice seedlings by 79.2% and 62.7% in T705 and by 57.3% and 24.1% in X24, respectively. The Cd2+ flux rate of high Cd-accumulation variety T705 was significantly higher than that of low Cd-accumulation variety X24. Under Burkholderia sp. Y4 inoculation, the yellow membrane was formed on the root surface of rice seedlings, and the Cd2+ flux rate in the elongation zone of T705 and X24 roots decreased by 36.0% and 35.0% in 3-day-old seedlings, as well as by 44.6% and 24.9% in 10-day-old seedlings, respectively. In conclusion, Burkholderia sp. Y4 inoculation inhibited the toxic effects of Cd on rice seedling growth through alleviating oxidative stress and damage caused by Cd. Furthermore, the root application of Burkholderia sp. Y4 effectively decreased the Cd2+ flux rate in the elongation zone of roots to inhibit the Cd uptake and accumulation in roots and shoots of rice seedlings. This study provides theoretical basis and data support for the application of Burkholderia sp. Y4 as a Cd-reducing and growth-promoting agent for rice in contaminated farmland. |
|
|
|
