Читать книгу Phytomicrobiome Interactions and Sustainable Agriculture - Группа авторов - Страница 17

Root exudate varies across the plant genotype and changes in root exudates of plant can be utilized in the breeding program for the enhancement of nutritional interaction among plants and microbes. For targeted breeding, perspective profiling of root exudates is essential for sustainable agriculture (Kuijken et al. 2015). This phenomenon is well‐known through exudate profiles among 19 natural Arabidopsis accessions, which shows a high variation in glycosylated and sulfated metabolites, plant hormones, salicylic acid catabolites, phenylpropanoids, coumarin scopoletin, and polyamine derivatives (Monchgesang et al. 2016). Similar studies were done and demonstrated about the rhizobacterial community composition influenced by varying exudation profiles (Micallef et al. 2009). Root exudate chemical composition changes in the condition of nutrient deprivation, which can further assist said breeding program. Few studies represent the effect of nutrient deficiency in the exudates, and the effect of phosphate limitation investigated in Arabidopsis results in the high abundance of oligolignols, which is responsible for lignifications and coumarins in low quantity (Ziegler et al. 2016). Particularly Fe‐deficient strawberry root exudates show a high content of dehydroascorbic acid, trans ferulic acid, galactonic acid, sucrose, and thymidine, whereas P‐deficient strawberry root exudates show higher concentration of malic acid, lysine, galactaricacid, butylamine, and simultaneously show a low concentration of ribonic acid, sorbitol 6 phosphate, and proline (Valentinuzzi et al. 2015).

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.