Drought stress threatens the ecological functions and economic value of grasses, posing a major challenge to their sustainable production. Plants co-evolve with rhizosphere microbial communities, sometimes described as the plant's second genome, that can contribute to drought adaptation. Drought alters root architecture, hormonal and redox regulation and belowground carbon allocation, thereby modifying the quantity and composition of root exudation and reshaping the rhizosphere environment. This review uses the rhizosphere dialogue as an integrative framework to link these plant responses with microbial recruitment and subsequent feedback to the host. We summarise three linked stages of this dialogue: drought-induced changes in root exudation; microbial recruitment and colonisation through chemotaxis, attachment, biofilm formation, and root colonisation; and microbiome-mediated feedback that improves plant water relations, hormonal and redox homoeostasis, nutrient acquisition, and root function. We highlight microbial extracellular polymeric substances, 1-aminocyclopropane-1-carboxylate deaminase, and microbial volatile organic compounds as key mediators of drought alleviation. We then discuss how this framework may inform rational synthetic microbial community (SynCom) design, microbiome-informed breeding, artificial intelligence and machine-learning assisted strain prioritisation, rhizosphere legacy effects, and real-time monitoring. Future work should distinguish active exudate-mediated recruitment from drought-driven environmental filtering and integrate multi-omics, plant genetics, functional validation, and multi-location field trials to determine whether rhizosphere dialogue can become a predictive framework for climate-resilient grass production.
Jin-Jin Liang, Wen-Li Ding, Xing-Xu Zhang et al.· Plant, Cell and Environment· 0 citations
Green manure can improve soil fertility by influencing the structure of the soil microbial community and enzyme activity, which in turn affects the main cropping system, and can reduce the use of chemical fertilizers and pesticides, thus reducing environmental pollution. In this study, we reviewed the literature on different green manure cropping patterns, focusing on the effects of different green manure cropping patterns on soil microbial communities, soil enzyme activities, soil physicochemical properties, and the main crop diseases, pests, weeds, and agronomic traits, etc. The positive effects produced by green manure are mainly reflected in the following aspects: (1) improving soil physicochemical properties and soil enzyme activities; (2) influencing soil microbial diversity; (3) improving the overall health of the main crop; (4) increasing the yield of the main crop. This study systematically summarizes the green manure planting patterns and their effects on the main crops, and provides a theoretical basis for green manure planting to solve crop succession barriers and enhance soil fertility; in addition, green manure has a positive effect on the conservation of soil microbial diversity, improves soil quality, and enhances agricultural production, which contributes to the sustainable development of agriculture. Accordingly, this review systematically summarizes green manure cultivation patterns and synthesizes available literature concerning the ecological functions of green manures, including their modulating impacts on soil physicochemical characteristics, microbial assemblages, pests, pathogens, weeds, and crop productivity. Moreover, it identifies key research challenges in this field and proposes outlooks for the sustainable utilization and prospective development of green manures within agroecosystems.
