دانلود رایگان مقاله انگلیسی فاکتورهای میکروبی به عنوان القا کننده های رشد گیاه - نشریه الزویر

ABSTRACT

Agricultural practices require novel products that allow sustainable development and commercial production according to the needs of farmers and consumers. Therefore, in the last decade, eco-friendly alternatives have been studied, so volatile organic compounds (VOCs) emitted by microorganisms have emerged as a cheaper, effective, efficient, and an eco-friendly alternative. VOCs are lipophilic compounds derived from microbial metabolic pathways with low molecular weight (< 300 g mol−1 ), low boiling point, and high vapor pressure that allow them to act as signal molecules over short and long distances. Main case studies provide evidence that VOCs released from diverse microorganisms (i.e. Bacillus, Pseudomonas, Arthrobacter, Fusarium, and Alternaria) can stimulate growth on a specific “target” seedling, such as Arabidopsis and tobacco. Some identified compounds, such as 3-hydroxy-2-butanone (acetoin), 2,3-butanediol, 2-pentylfuran, or dimethylhexadecylmine have shown their ability to elicit growth at root or leaf level. Few studies indicate that VOCs act in the regulation at phytohormone, metabolic pathways and nutrition levels according to genetic, proteomic, and metabolic analyses; but action mechanisms associated with growth-inducing activity are poorly understood. In this work, we reviewed case studies regarding identified compounds and action mechanisms for a better understanding of the information collected so far. Additionally, a brief description about the effects of VOCs for induction of resistance and tolerance in plants are presented, where compounds such as acetoin, dimethyl disulfide, 3-pentanol and 6- pentyl-α-pyrone have been reported. Furthermore, we summarized the knowledge to direct future studies that propose microbial VOCs as a technological innovation in agriculture and horticulture.

8. Perspectives and conclusions

Recent advances have shown that VOCs emitted by microorganisms associated with root plants can be a novel strategy to be applied as growth inducers with potential use in agricultural species. Studies have contributed with relevant evidence that VOCs have the ability to act as signal molecules for eliciting growth, but there is a need to research the emission of volatiles from diverse microorganisms and their ability to act on one or more plant species. Another challenge is the evaluation of the specificity of single or mixture compounds previously identified under laboratory conditions to check their capacity to induce growth, characterizing their action mode. To date, researches on action mode of a specific compound to determine its effect on the regulation of cellular and metabolic processes to elicit growth should be elucidated. Therefore, proteomic, molecular and metabolomic techniques must be carried out to achieve a better understanding of the matter. In addition, a greater progress is required to implement the application of VOCs under field conditions. Therefore, experimental setups should be designed in order to investigate and standardize methodologies and formulations to mimic rhizosphere conditions. New techniques will help to evaluate the effects on plant growth required to prove that microbial VOCs can be an innovative technology to be applied in agricultural crops and a novel alternative to provide sustainable agricultural products that farmers and consumers need. The Fig. 8 represents the summary of knowledge to propose future studies that contribute with to better understand of action mode of VOCs and the possibility to implement as strategy tool.