Climatic change and extreme weather events have become a major threat to global agricultural productivity. Plants coexist with microorganisms, which play a significant role in influencing their growth and functional traits. The rhizosphere serves as an ecological niche encompassing plant roots and is a chemically complex environment that supports the growth and development of diverse plant-interactive microbes. Although plant-microbe interactions have been extensively investigated however, limited exploration have been made how abiotic stresses affect the structure and assembly of microbial communities in the rhizosphere. This review highlights climate change influence on plant growth, functional traits, and microbial communities. It explores plant mechanisms for mitigating abiotic stress, such as removing reactive oxygen species (ROS), regulating antioxidant activity and indole-3-acetic acid (IAA) production, and controlling growth-inhibitory ethylene levels through colonization by bacteria producing ACC deaminase. Additionally, we elaborated the systematic communicatory network steered by hormonal crosstalk and root exudation, which can modulate and initiate the dialogues between plants and surrounding microbes. This network ultimately promotes the chemotactic movement of microbes towards the rhizosphere, facilitating their early colonization. Finally, we reviewed the recent advancements for understanding how plant-microbe interactions foster resilience under climate stress.
The area of salinized land is gradually expanding cross the globe. Salt stress seriously reduces the yield and quality of crops and endangers food supply to meet the demand of the increased population. The mechanisms underlying nano-enabled plant tolerance were discussed, including (1) maintaining ROS homeostasis, (2) improving plant’s ability to exclude Na+and to retain K+, (3) improving the production of nitric oxide, (4) increasing α-amylase activities to increase soluble sugar content, and (5) decreasing lipoxygenase activities to reduce membrane oxidative damage. The possible commonly employed mechanisms such as alleviating oxidative stress damage and maintaining ion homeostasis were highlighted. Further, the possible role of phytohormones and the molecular mechanisms in nano-enabled plant salt tolerance were discussed. Overall, this review paper aims to help the researchers from different field such as plant science and nanoscience to better understand possible new approaches to address salinity issues in agriculture.
It is well studied that potassium (K+) deficiency induced aberrant growth and development of plant and altered the expression of protein-coding genes. However, there are not too many systematic investigations on root development affected by K+ deficiency, and there is no report on miRNA expression during K+ deficiency in wheat. In this study, we found that K+ deficiency significantly affected wheat seedling growth and development, evidenced by reduced plant biomass and small plant size. In wheat cultivar AK-58, up-ground shoots were more sensitive to K+ deficiency than roots. K+ deficiency did not significantly affect root vitality but affected root development, including root branching, root area, and root size. K+ deficiency delayed seminal root emergence but enhanced seminal root elongation, total root length, and correspondingly total root surface area. K+ deficiency also affected root and leaf respiration at the early exposure stage, but these effects were not observed at the later stage. One potential mechanism causing K+ deficiency impacts is microRNAs (miRNAs), one important class of small regulatory RNAs. K+ deficiency induced the aberrant expression of miRNAs and their targets, which further affected plant growth, development, and response to abiotic stresses, including K+ deficiency. Thereby, this positive root adaption to K+ deficiency is likely associated with the miRNA-involved regulation of root development.
1 August 2020 in Plant Physiology and Biochemistry
Difenoconazole is one of the most commonly used fungicides to prevent and treat plant diseases caused by certain fungi. Due to increasing usage, more difenoconazole has been released into the environment and caused environment pollution. However, the potential impact of difenoconazole on plant growth and development and its involved mechanism are unclear. In this study, we discovered that difenoconazole exposure significantly inhibited plant growth, evidenced by the decrease in root dry weight, total root length, and surface area by 20–70%, 43–73%, and 26–66%, respectively, under different regimes of treatment concentrations and periods. Difenoconazole exposure also significantly inhibited shoot growth and development by decreasing 33–61% of the shoot dry weight and 50–65% of the leaf area. Difenoconazole exposure induced plant leaf cells to generate more ROS (O2•− and H2O2) and MDA, which resulted in a decreased chlorophyll content and then inhibited leaf photosynthesis. Difenoconazole exposure also induced the activities of superoxide dismutase (SOD), catalase (CAT), guaiacol peroxidase (G-POD), and ascorbate peroxidase (APX) in the roots and leaves of the wheat seedlings. SOD and APX activities were higher and more stable in the roots than those in the leaves. Based on our study, plant roots exhibited a more pronounced superoxide radical scavenging ability than plant leaves. In summary, difenoconazole exposure caused oxidative stress, reduced chlorophyll biosynthesis and functions, and then inhibited wheat plant growth and development.