Bao Xin-Guang, Chong Pei-Fang, He Cai, Lu Xue-Mei, Wang Xue-Ying, Zhang Feng, Tan Bing-Bing, Yang Jia-Li, Gao Li-Li
Key Laboratory of Grassland Ecosystem, Gansu Agricultural University, Ministry of Education, Lanzhou, China.
College of Forest of Gansu Agriculture University, Lanzhou, China.
Front Plant Sci. 2025 Jan 3;15:1502659. doi: 10.3389/fpls.2024.1502659. eCollection 2024.
Soil salinization poses a significant ecological and environmental challenge both in China and across the globe. Plant growth-promoting rhizobacteria (PGPR) enhance plants' resilience against biotic and abiotic stresses, thereby playing a vital role in soil improvement and vegetation restoration efforts. PGPR assist plants in thriving under salt stress by modifying plant physiology, enhancing nutrient absorption, and synthesizing plant hormones. However, the mechanisms through which PGPR regulate the contents of carbon (C) and nitrogen (N), and biomass allocation of desert plant in response to salt stress is still unclear. This study explores the impact of PGPR on biomass allocation, C, and N contents of seedlings through a pot experiment. Strains P6, N20, and N21, identified as , were isolated from the rhizosphere of , and they exhibited various beneficial traits such as indole-3-acetic acid (IAA) production, phosphate solubilization, nitrogen fixation, and tolerance to up to 8% NaCl stress. We found that under NaCl stress, seedlings exhibit significant reductions in plant height, basal diameter, and root surface area (<0.05). However, inoculation with strains P6, N20, and N21 reverses these trends. Compared to NaCl treatment alone, co-treatment with these strains significantly increases the biomass of roots, stems, and leaves, particularly root biomass, which increases by 99.88%, 85.55%, and 141.76%, respectively (<0.05). Moreover, N contents decrease significantly in the roots, stems and leaves, C contents increase significantly in the roots and leaves compared to NaCl treatment (0.05). Specifically, N contents in roots decrease by 14.50%, 12.47%, and 8.60%, while C contents in leaves increase by 4.96%, 4.45%, and 4.94%, respectively (<0.05). Additionally, stem and leaf biomasses exhibit a significant positive correlation with C contents and a significant negative correlation with N contents in these tissues. In conclusion, inoculation of strains enhanced the biomass of seedlings, regulated the biomass distribution, and modifies C and N contents to promote plant growth and improve salt stress tolerance. This study provides a novel adaptive strategy for the integrated use of PGPR and halophytes in saline-alkali soil improvement and vegetation restoration efforts.
土壤盐渍化在中国乃至全球都构成了重大的生态和环境挑战。植物促生根际细菌（PGPR）可增强植物对生物和非生物胁迫的抵御能力，从而在土壤改良和植被恢复工作中发挥重要作用。PGPR通过改变植物生理、增强养分吸收和合成植物激素，帮助植物在盐胁迫下茁壮成长。然而，PGPR响应盐胁迫调节沙漠植物碳（C）和氮（N）含量以及生物量分配的机制仍不清楚。本研究通过盆栽试验探究了PGPR对幼苗生物量分配、C和N含量的影响。从[具体植物名称]根际分离出的菌株P6、N20和N21被鉴定为[具体菌株名称]，它们表现出各种有益特性，如吲哚-3-乙酸（IAA）产生、解磷、固氮以及耐受高达8% NaCl胁迫。我们发现，在NaCl胁迫下，[具体植物名称]幼苗的株高、基径和根表面积显著降低（<0.05）。然而，接种菌株P6、N20和N21可扭转这些趋势。与单独的NaCl处理相比，与这些菌株共同处理显著增加了根、茎和叶的生物量，尤其是根生物量，分别增加了99.88%、85.55%和141.76%（<0.05）。此外，与NaCl处理相比，根、茎和叶中的N含量显著降低，根和叶中的C含量显著增加（P<0.05）。具体而言，根中的N含量分别降低了14.50%、12.47%和8.60%，而叶中的C含量分别增加了4.96%、4.45%和4.94%（<0.05）。此外，茎和叶生物量与这些组织中的C含量呈显著正相关，与N含量呈显著负相关。总之，接种[具体植物名称]菌株提高了[具体植物名称]幼苗的生物量，调节了生物量分布，并改变了C和N含量，以促进植物生长并提高耐盐胁迫能力。本研究为PGPR和盐生植物在盐碱地改良和植被恢复工作中的综合利用提供了一种新的适应性策略。
