Montero-Palmero Belén, Lucas Jose A, Montalbán Blanca, García-Villaraco Ana, Gutierrez-Mañero Javier, Ramos-Solano Beatriz
Plant Physiology, Pharmaceutical and Health Sciences Department, Faculty of Pharmacy, San Pablo-CEU Universities, 28668 Boadilla del Monte, Spain.
Plants (Basel). 2024 Dec 22;13(24):3585. doi: 10.3390/plants13243585.
An alkaline pH in soils reduces Fe availability, limiting Fe uptake, compromising plant growth, and showing chlorosis due to a decrease in chlorophyll content. To achieve proper Fe homeostasis, dicotyledonous plants activate a battery of strategies involving not only Fe absorption mechanisms, but also releasing phyto-siderophores and recruiting siderophore-producing bacterial strains. A screening for siderophore-producing bacterial isolates from the rhizosphere of was carried out, resulting in two strains, Z8.8 and Z10.4, with an outstanding in vitro potential to solubilize Fe, Mn, and Co. The delivery of each strain to 4-week-old iron-starved tomatoes reverted chlorosis, consistent with enhanced Fe contents up to 40%. Photosynthesis performance was improved, revealing different strategies. While Z8.8 increased energy absorption together with enhanced chlorophyll "a" content, followed by enhanced energy dissipation, Z10.4 lowered pigment contents, indicating a better use of absorbed energy, leading to a better survival rate. The systemic reprogramming induced by both strains reveals a lower expression of Fe uptake-related genes, suggesting that both strains have activated plant metabolism to accelerate Fe absorption faster than controls, consistent with increased Fe content in leaves (47% by Z8.8 and 42% by Z10.4), with the difference probably due to the ability of Z8.8 to produce auxins affecting root structure. In view of these results, both strains are effective candidates to develop biofertilizers.
土壤中的碱性pH值会降低铁的有效性，限制铁的吸收，影响植物生长，并因叶绿素含量降低而出现黄化现象。为了实现适当的铁稳态，双子叶植物会激活一系列策略，不仅涉及铁吸收机制，还包括释放植物铁载体和招募产生铁载体的细菌菌株。对[具体植物名称]根际产生铁载体的细菌分离株进行了筛选，得到了两株菌株Z8.8和Z10.4，它们在体外具有出色的溶解铁、锰和钴的潜力。将每种菌株施用于4周龄缺铁的番茄后，黄化现象得到缓解，铁含量提高了40%。光合作用性能得到改善，显示出不同的策略。Z8.8增加了能量吸收以及叶绿素“a”含量，随后增强了能量耗散，而Z10.4降低了色素含量，表明其对吸收能量的利用更好，从而导致更高的存活率。两种菌株诱导的系统性重编程显示铁吸收相关基因的表达降低，这表明两种菌株都激活了植物代谢，以比对照更快地加速铁吸收，这与叶片中铁含量的增加一致（Z8.8增加了47%，Z10.4增加了42%），差异可能是由于Z8.8产生生长素影响根系结构的能力。鉴于这些结果，这两种菌株都是开发生物肥料的有效候选菌株。
