Abstract
Biofertilizer production and application for sustainable agriculture is already a reality. The methods for biofertilizers delivery in crop fields are diverse. Although foliar spray is gaining wide acceptance, little is known about the influence that the biochemical features of leaves have on the microbial colonization. Arthrobacter agilis UMCV2 is a rhizospheric and endophytic bacteria that promotes plant growth and health. In this study, we determined the capacity of the UMCV2 strain to colonize different leaves from Medicago truncatula in a foliar inoculation system. By using two powerful analytical methods based on mass spectrometry, we determined the chemical profile of the leaves in 15-d old plants. The metabolic signatures between the unifoliate leaf (m1) and the metameric units developing above (m2 and m3) were different, and interestingly, the highest colony forming units (CFU) was found in m1. The occurrence of the endophyte strongly affects the sugar composition in m1 and m2 leaves. Our results suggest that A. agilis UMCV2 colonize the leaves under a foliar inoculation system independently of the phenological age of the leaf and it is capable of modulating the carbohydrate metabolism without affecting the rest of the metabolome.
Highlights
Plants live in a close relationship with different microbial communities that reside inside or outside the plant tissues
The principal component analysis (PCA) from the selected ions displayed a group belonging to m1 with an error of less than 1% (Fig. 2b), the separation of m1 from m2 and m3 was even greater after the ion selection (Figs. 1c and 2b)
These results suggest that the physiological condition of the m1 leaf has a clearly distinct metabolic identity compared to the m2 and m3 leaves, which presented the same chemical profile at the time of harvest
Summary
Plants live in a close relationship with different microbial communities that reside inside or outside the plant tissues. Studies of the functional capacity of beneficial endophytes have revealed their potential as promoters of plant growth and health, they are free from the environmental pressure of changing soil and climate conditions experienced by their rhizospheric counterparts, so they are an excellent candidate for biofertilizers[10,11]. A study using the DLI-ESI-MS method showed that volatiles from A. agilis UMCV2 induce the accumulation of different metabolites involved in the iron-adaptive processes in Medicago truncatula[16]. Foliar inoculation could be a delivery method for introducing A. agilis UMCV2 into fields in order to enhance the plant growth and crop production, it is timely to conduct a metabolomic approach to determine whether the interconnected leaf phenological age and chemical composition influence the growth of the endophytes in the leaves, and at the same time to gain insight into plant response to the endophytic colonization
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
