异养氨氧化细菌通过双重作用机制促进多花黑麦草的再生  

Heterotrophic ammonia-oxidizing bacteria promote regeneration of Italian ryegrass via a dual-action mechanism

作　　者：于浩 王晓凌[1] 段义忠[2] 司振强 熊翔英 吴迪 李亚楠 YU Hao;WANG Xiaoling;DUAN Yizhong;SI Zhenqiang;XIONG Xiangying;WU Di;LI Ya’nan(College of Agriculture,Henan University of Science and Technology,Luoyang 471000,Henan,China;College of Life Sciences,Yulin University,Yulin 719000,Shaanxi,China)

机构地区：[1]河南科技大学农学院,河南洛阳471000 [2]榆林学院生命科学学院,陕西榆林719000

出　　处：《微生物学通报》2024年第8期2962-2973,共12页Microbiology China

基　　金：国家自然科学基金(U1304326);河南省科学委员会优秀青年基金(174100510004);河南省自然科学基金(162300410070)。

摘　　要：【背景】异养氨氧化细菌(heterotrophic ammonia-oxidizing bacteria,HAOB)通过增加叶片细胞分裂素含量促进多花黑麦草的再生,但其促进植物再生的具体机制尚未探明。【目的】揭示HAOB调控细胞分裂素的合成促进多花黑麦草再生的机制。【方法】以一株HAOB菌株(S2_8_1)为试验菌株,盆栽多花黑麦草作为植物材料。试验处理设计包括:常规供水(TA);添加空白富集培养基(TB);添加硝化抑制剂3,4-二甲基吡唑磷酸盐(3,4-dimethylpyrazole phosphate,DMPP)(TN1);添加DMPP和20 mmol/L的NO_(3)^(−)-N(TN2);添加DMPP和30 mmol/L的NO3−-N(TN3);添加DMPP和40 mmol/L的NO_(3)^(−)-N(TN4);接种菌株S2_8_1(TI)。【结果】30−40 mmol/L NO_(3)^(−)-N对提高叶片细胞分裂素含量和根向叶片传递效果最好,从而促进叶片再生。在根际土壤硝化作用诱导的细胞分裂素增加达到最大限度时,接种菌株S2_8_1进一步增加了根中细胞分裂素的合成,提高了叶片中细胞分裂素的浓度。所测试的HAOB菌株S2_8_1通过双重作用显著提高了叶片细胞分裂素的浓度,促进了多花黑麦草再生。【结论】本研究揭示了HAOB菌株在根际发挥双重作用促进植物生长的机制,为提高牧草产量和农业可持续发展提供直接应用价值。[Background]Heterotrophic ammonia-oxidizing bacteria(HAOB)promote the regeneration of Italian ryegrass by increasing the content of leaf cytokinins,although the specific mechanism remains to be elucidated.[Objective]To elucidate how HAOB promote the regeneration of Italian ryegrass by regulating the synthesis of cytokinins via a dual-action mechanism in the rhizosphere soil and outside the rhizosphere environment,respectively.[Methods]A strain(S2_8_1)of HAOB and potted Italian ryegrass were used in this study.The treatments were designed as follows:Regular watering(TA);Addition of blank medium for enrichment culture(TB);Addition of 3,4-dimethylpyrazole phosphate(DMPP)(TN1);Addition of DMPP and 20 mmol/L NO_(3)^(−)-N(TN2);Addition of DMPP and 30 mmol/L NO_(3)^(−)-N(TN3);Addition of DMPP and 40 mmol/L NO_(3)^(−)-N(TN4);Inoculation with the strain S2_8_1(TI).[Results]NO_(3)^(−)-N of 30–40 mmol/L was most effective in increasing the content of leaf cytokinins and enhancing the transfer of these hormones from the roots to the leaves,thereby promoting leaf regeneration.When the nitration-induced increase in cytokinins in the rhizosphere soil reached the maximum,inoculation with strain S2_8_1 further boosted the synthesis of these hormones in the roots,leading to an increased concentration of cytokinins in the leaves.The HAOB strain S2_8_1 significantly elevated the level of cytokinins in leaves via a dual-action mechanism,thereby promoting the regeneration of Italian ryegrass.[Conclusion]This study unveils the dual-action mechanism by which HAOB strains in the rhizosphere enhance plant growth,offering a direct application value for improving forage yields and sustainable agriculture development.

关 键 词：异养氨氧化细菌 细胞分裂素 多花黑麦草 再生 土壤硝化作用 

分 类 号：S543.6[农业科学—作物学]