Journal of Integrative Agriculture ›› 2025, Vol. 24 ›› Issue (5): 1738-1753.DOI: 10.1016/j.jia.2024.01.033

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秋茄树胎生苗中响应盐度变化的内生细菌可增强水稻的耐盐能力

  

  • 收稿日期:2023-08-15 修回日期:2024-01-24 接受日期:2023-11-27 出版日期:2025-05-20 发布日期:2025-04-14

Salinity-responsive key endophytic bacteria in the propagules of Kandelia obovata enhance salt tolerance in rice

Zhian Dai1, Rongwei Yuan1, Xiangxia Yang1, Hanxiao Xi1, Ma Zhuo1, Mi Wei1, 2#   

  1. 1 School of Agriculture and Biotechnology, Shenzhen Campus of Sun Yat-sen University, Shenzhen 518107, China

    2 Key Laboratory for Quality Control of Characteristic Fruits and Vegetables of Hubei Province/College of Life Science and Technology, Hubei Engineering University, Xiaogan 432000, China

  • Received:2023-08-15 Revised:2024-01-24 Accepted:2023-11-27 Online:2025-05-20 Published:2025-04-14
  • About author:#Correspondence Mi Wei, E-mail: weim29@mail.sysu.edu.cn
  • Supported by:
    This work was supported by funds from the National Natural Science Foundation of China (32270296), the Natural Science Foundation of Guangdong Province, China (2024A1515010498), the Shenzhen Postdoctoral Scientific Research, China (77000-42100004), and the Fundamental Research Funds for the Central Universities, Sun Yat-sen University, China.

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摘要：

盐度是影响全球作物生长和产量的主要环境胁迫。应用耐盐植物促生长菌（HT-PGPB）促进作物生长、降低盐胁迫的不利影响已得到广泛认可。本研究通过对秋茄树（Kandelia ovate）繁殖体中微生物群落的分析，确定了能够响应盐度变化的关键内生细菌。通过纯培养获得在氯化钠（NaCl）浓度为5%（w/v）的高盐条件下正常生长的Delftia tsuruhatensis DYX29菌株。DYX29可以合成铁载体（单位值为87.6%）和ACC（1-氨基环丙烷-1-羧酸）脱氨酶（29 U L-1），并能在高盐度条件下更多合成胞内氨基酸和生长素。接种DYX29能显著提高水稻的耐盐性。在盐胁迫下，添加DYX29通过多种途径有效促进了水稻幼苗的生长。水稻幼苗的生物量（干重）提高了32.9%，促进可溶性糖的积累提高23.1%。水稻叶片CAT和POD活性分别提高了37.8%和88.2%。同时，它还能维持根和叶的离子稳态。另外，水稻根系中促生长激素IAA、BL、ABA和SA的表达分别上调27.8%、69.5%、123.7%和28.6%。本研究为从红树林生态系统中筛选有价值的耐盐益生菌以促进盐胁迫下作物的生长提供了启示，也可为新型耐盐益生菌生物肥料的开发及相关机制的研究提供有益的参考。

Abstract:

Salinity is a major environmental stress affecting crop growth and productivity globally.  The application of halo-tolerant plant growth-promoting bacteria (HT-PGPB) has been widely recognized to promote crop growth and reduce the adverse effects of salt stress.  In this study, key endophytic bacteria that can respond to salinity changes were identified by analyzing the microbial community in propagules of Kandelia obovata.  Delftia tsuruhatensis DYX29, a strain that can grow normally under high salinity conditions with a sodium chloride (NaCl) concentration of 5% (w/v), was obtained by pure culture.  DYX29 can produce siderophores with a siderophore unit value of 87.6% and 1-aminocyclopropane-1-carboxylate (ACC) deaminase with 29 U L–1, and its synthesis of intracellular amino acids and auxin can be induced by high salinity.  Inoculation with DYX29 can remarkably promote the salt tolerance of rice.  Under salt stress, the addition of DYX29 was shown to effectively promote the growth of rice seedlings through a variety of approaches.  It increased the biomass of rice seedlings by 32.9% (dry weight) and promoted the accumulation of soluble sugars by 23.1%.  It also increased catalase (CAT) and peroxidase (POD) activities in rice leaves by 37.8 and 88.2%, respectively.  Moreover, it maintained the ionic homeostasis in rice roots and leaves.  In addition, it upregulated the expression of growth-promoting hormones, such as indole-3-acetic acid (IAA), brassinolide (BL), abscisic acid (ABA), and salicylic acid (SA), in rice roots by 27.8, 69.5, 123.7 and 28.6%, respectively.  This study provides inspiration for screening valuable salt-tolerant pro-biotic bacteria from mangrove ecosystems and their use for crop growth promotion under salt stress.  It can also provide useful references for the development of new salt-tolerant and pro-biotic biofertilizers, as well as the investigation of the related mechanisms.


Key words: salt stress , halo-tolerant plant growth-promoting bacteria , Delftia tsuruhatensis , microbial community