Ben-Jabeur Maissa, Kthiri Zayneb, Jallouli Salma, Harbaoui Kalthoum, Chamekh Zoubeir, Ayadi Sawsen, Trifa Youssef, Hamada Walid
Carthage University, Laboratory of Genetics and Cereal Breeding (LR14 AGR01), The National Agronomic Institute of Tunisia, Tunis, Tunisia.
Carthage University, Higher Institute of Preparatory Studies in Biology and Geology (ISEP BG), Soukra, Tunisia.
PLoS One. 2025 Aug 18;20(8):e0329619. doi: 10.1371/journal.pone.0329619. eCollection 2025.
Despite the significant increase in the use of plant growth-promoting bacteria (PGPB) in agriculture, there is a dearth of studies addressing the impact of seed coating with PGPB on plant productivity. The main objective of this research is to evaluate the potential of Bacillus safensis strain B7 as a seed coating agent to confer plant growth promotion and tolerance against biotic and abiotic stress. The whole-genome sequencing of strain B7 was also performed to study its genomic features. The effect of seed coating with strain B7 was assessed on seed water uptake, germination and seedling dry weight under controlled conditions. Besides, the direct and indirect effect against biotic stress was evaluated through antifungal activity and potential in stimulating the induced systemic resistance (ISR) under controlled conditions. Afterwards, the effect was evaluated in the field under drought stress conditions, based on the traits of grain yield (GY), straw yield, number of spikes/m2, and thousand kernel weight (TKW). It is noticeable that seed coating with strain B7 resulted in greater and faster water uptake. Germination and plant growth similarly boosted. Strain B7 was able to hamper the mycelial growth of F. culmorum and S. sclerotiorum and to induce ISR, after B. cinerea infection, in melon leaves taken from root-treated plants. In the field, seed coating with strain B7 improved wheat performance under the different environments and mitigated the effect of drought on spikes/m2, GY and TKW. The observed impact on wheat plants is supported by genomic analysis of strain B7 showing the presence of genes related to beneficial plant-bacteria interactions involved in plant colonization, growth promotion and alleviation of stress. Therefore, B. safensis strain B7 has promising applications in the seed treatment industry to increase plant yield and alleviate the impact of stress.
尽管农业中促植物生长细菌（PGPB）的使用显著增加，但针对用PGPB进行种子包衣对植物生产力影响的研究却很匮乏。本研究的主要目的是评估安全芽孢杆菌菌株B7作为种子包衣剂促进植物生长以及赋予植物对生物和非生物胁迫耐受性的潜力。还对菌株B7进行了全基因组测序以研究其基因组特征。在可控条件下评估了用菌株B7进行种子包衣对种子水分吸收、发芽和幼苗干重的影响。此外，在可控条件下通过抗真菌活性和刺激诱导系统抗性（ISR）的潜力评估了对生物胁迫的直接和间接影响。之后，基于籽粒产量（GY）、秸秆产量、每平方米穗数和千粒重（TKW）等性状，在干旱胁迫条件下的田间评估了其效果。值得注意的是，用菌株B7进行种子包衣导致水分吸收更快且更多。发芽和植物生长同样得到促进。菌株B7能够抑制禾谷镰刀菌和核盘菌的菌丝生长，并在灰葡萄孢感染后，在经根部处理的甜瓜植株的叶片中诱导ISR。在田间，用菌株B7进行种子包衣改善了不同环境下小麦的表现，并减轻了干旱对每平方米穗数、GY和TKW的影响。对菌株B7的基因组分析表明存在与有益植物 - 细菌相互作用相关的基因，这些基因参与植物定殖、生长促进和胁迫缓解作用，从而支持了观察到的对小麦植株的影响。因此，安全芽孢杆菌菌株B7在种子处理行业具有增加植物产量和减轻胁迫影响的广阔应用前景。
