Phytomicrobiome Interactions and Sustainable Agriculture

In the environment, plants are exposed to all kinds of friendly and unfriendly microbes with several stresses in the ground. Plant secretion called root exudate has a lot of potential from the perspective of defense. Root exudates possess antimicrobial chemicals, such as phytoanticipins, diterpene rhizathalene A, phytoalexins, phenylpropanoids, t‐cinnamic acids, momilacton A, rosmarinic acids, terpenoids, benzoxazinoids, and the defense signaling molecules, salicylic acid, nitric oxide, and methyl jasmonate, which assist in the defense mechanisms of the plant. In addition, these chemical phenolics and terpenoids act as an antimicrobial apart from defense root exudates, which support the stress condition of plants due to their primary and secondary metabolite present in root exudates ( Table 1.2).

Plant root exudation indirectly controls resource competition by altering soil chemistry, soil process, and microbial populations, and thus has an important function in plant development. Root exudation possesses the capacity to alter the soil nutrient availability by changing the soil property in the aspect of its chemistry and biology. Root exudate releases mucilaginous substance from root tip of the plant and is a part of exudation quite essential to maintain the water potential (Susan 2018). Root exudate releases plant carbon compounds (border cells and exudates) and primary metabolites into the rhizospheric soil (Canarini et al. 2019). It is important to understand root‐mediated communication between plants and other organisms, which assists in the enhancement of agricultural production and can be useful in reduction in the demand for chemical fertilizer, such as in legume plants.

Today's main concern of agriculture is the quality of productivity in order to feed the world population. For more production and protection of crops, farmers use chemicals that directly or indirectly effects the fertility of the soil as well as the consumers of the crop. To alleviate the chemical inputs in the agriculture requires detailed information about root exudation and its influence on plant development through soil condition modulation in terms of both biotic as well as abiotic components. Production of the crop depends on plant genotype and soil ecosystem. Root exudate is the key factor in the rhizospheric interaction due to nutrient assets. Researchers should emphasize root exudates, through profiling and their impact on microbes and soil in the rhizosphere for more exploration of root exudate. Still there are several unexplored chemicals of root exudates that can create magnificent changes in the soil and plants in terms of fertility, defense, growth, and yield. A few relevant and essential components of root exudates can be used for developing variety through genetic engineering and breeding, which assists in a sustainable agriculture system. Several chemical inducers should be explored, which increases the quantity of root exudates for better performance of the rhizosphere. In conclusional, in revealing root exudation secrets, we can support economical agricultural productivity through achievement of environmental sustainability.

Table 1.2 Developments in root exudate studies and their action mechanism.