Halo Boshra Ahmed, Aljabri Yaqeen A S, Yaish Mahmoud W
Department of Biology, College of Sciences, Sultan Qaboos University, Muscat, Oman.
PLoS One. 2025 Mar 25;20(3):e0320197. doi: 10.1371/journal.pone.0320197. eCollection 2025.
Rhizospheric bacterial communities in plants contribute to drought resilience by promoting plant-soil interactions, yet their biodiversity and ecological impacts are not fully characterized. In cowpeas, these interactions may be crucial in enhancing tolerance to drought conditions. In this study, cowpea plants were subjected to drought treatment, the soil attached to the roots was collected, environmental DNA (e-DNA) was extracted, and the bacterial communities were identified as amplicon sequence variants (ASVs) by metagenomics analysis of the 16S rRNA gene. Microbial communities under drought and control conditions were analyzed using taxonomy and diversity metrics. The sequencing results revealed 5,571 ASVs, and taxonomic analysis identified 1,752 bacterial species. Alpha and beta diversity analyses showed less conserved microbial community structures and compositions among the samples isolated from the rhizosphere under drought conditions compared to untreated samples, implying the enhancement effect of drought on species' biodiversity and richness. The differential accumulation analysis of the bacterial community identified 75 species that accumulated significantly (P ≤ 0.05) in response to drought, including 13 species exclusively present, seven absent, and 46 forming a high-abundance cluster within the hierarchical heatmap. These species were also grouped into specific clades in the phylogenetic tree, suggesting common genetic ancestry and potentially shared traits associated with drought tolerance. The differentially accumulated bacterial list included previously characterized species from drought and saline habitats. These findings suggest that drought stress significantly alters the composition and abundance of epiphytic bacterial communities, potentially impacting the rhizosphere's ecological balance and interactions with cowpeas. The results highlight microbial adaptations that enhance plant resilience through improved stress mitigation, providing meaningful understandings for advancing sustainable agriculture and developing microbial-based strategies to boost crop productivity in drought-prone regions.
植物根际细菌群落通过促进植物与土壤的相互作用,有助于提高植物的抗旱能力,但其生物多样性和生态影响尚未得到充分表征。在豇豆中,这些相互作用对于增强对干旱条件的耐受性可能至关重要。在本研究中,对豇豆植株进行干旱处理,收集根系附着的土壤,提取环境DNA(e-DNA),并通过对16S rRNA基因的宏基因组分析将细菌群落鉴定为扩增子序列变体(ASV)。使用分类学和多样性指标分析干旱和对照条件下的微生物群落。测序结果显示有5571个ASV,分类学分析鉴定出1752种细菌。α和β多样性分析表明,与未处理的样品相比,干旱条件下从根际分离的样品中微生物群落结构和组成的保守性较低,这意味着干旱对物种生物多样性和丰富度有增强作用。细菌群落的差异积累分析确定了75种对干旱有显著积累(P≤0.05)的物种,包括13种仅存在的物种、7种不存在的物种以及46种在层次热图中形成高丰度簇的物种。这些物种在系统发育树中也被归为特定的进化枝,表明它们有共同的遗传祖先以及可能与耐旱性相关的共同特征。差异积累的细菌列表包括先前在干旱和盐碱生境中已表征的物种。这些发现表明,干旱胁迫显著改变了附生细菌群落的组成和丰度,可能影响根际的生态平衡以及与豇豆的相互作用。结果突出了微生物通过改善压力缓解来增强植物恢复力的适应性,为推进可持续农业和制定基于微生物的策略以提高干旱易发地区的作物生产力提供了有意义的认识。