Tan Deguan, Fu Lili, Yu Ying, Sun Xuepiao, Zhang Jiaming
National Key Laboratory for Tropical Crop Breeding, Institute of Tropical Bioscience and Biotechnology, Sanya Research Institute of Chinese Academy of Tropical Agricultural Sciences, Haikou, China.
Hainan Key Laboratory of Microbiological Resources, Hainan Institute for Tropical Agricultural Resources, Chinese Academy of Tropical Agricultural Sciences, Haikou, China.
Front Plant Sci. 2024 Nov 13;15:1480588. doi: 10.3389/fpls.2024.1480588. eCollection 2024.
Ammonium is the preferred N nutrition over nitrate for some plant species, but it is toxic to many other plant species and induces senescence at high concentrations. The duckweed (Griff.) Kurz is the smallest and fast-growing angiosperm. It is highly sensitive to ammonium and has a short lifespan on media containing 0.5 mM or higher ammonia. This feature makes it a potential model plant to screen for anti-aging microorganisms. By co-culturing with endophytic microorgainisms isolated from rubber tree, we screened out an strain ITBB2-31 that significantly increased the lifespan and the biomass of . Interestingly, both filter-sterilized and autoclaved exudates of ITBB2-31 increased the lifespan of cultures from 1 month to at least 7 months. Meanwhile, the exudates also showed strong anti-aging effects on cassava and the rubber tree leaves and increased chlorophyll contents by 50% - 350%. However, high contents of filter-sterilized exudates inhibited the growth of while extending its lifespan, indicating that there were heat-sensitive growth-inhibiting agents in the exudates as well. Comparative metabolome analysis of the filter-sterilized and autoclaved exudates revealed multiple heat-stable anti-aging and heat-sensitive growth-inhibiting compounds. Our results suggest that can be served as a rapid and efficient model plant to screen for plant anti-aging microorganisms.
对于某些植物物种而言，铵态氮是比硝态氮更优质的氮素营养源，但对许多其他植物物种有毒，且在高浓度时会诱导衰老。浮萍（Lemna minor (Griff.) Kurz）是最小且生长迅速的被子植物。它对铵态氮高度敏感，在含有0.5 mM或更高氨的培养基上寿命较短。这一特性使其成为筛选抗衰老微生物的潜在模式植物。通过与从橡胶树分离的内生微生物共培养，我们筛选出了一株ITBB2 - 31菌株，该菌株显著延长了浮萍的寿命并增加了其生物量。有趣的是，ITBB2 - 31经过滤灭菌和高压灭菌的分泌物都将浮萍培养物的寿命从1个月延长至至少7个月。同时，这些分泌物对木薯和橡胶树叶片也显示出强大的抗衰老作用，并使叶绿素含量增加了50% - 350%。然而，经过滤灭菌的高含量分泌物在延长浮萍寿命的同时抑制了其生长，表明分泌物中也存在热敏感的生长抑制因子。对经过滤灭菌和高压灭菌的分泌物进行比较代谢组分析，揭示了多种热稳定的抗衰老化合物和热敏感的生长抑制化合物。我们的结果表明，浮萍可作为筛选植物抗衰老微生物的快速高效模式植物。
