Restrictive water condition modifies the root exudates composition during peanut-PGPR interaction and conditions early events, reversing the negative effects on plant growth

CESARI A; PAULUCCI N.; LOPEZ GOMEZ M; HIDALGO CASTELLANOS J; LLUCH PLÁ C; DARDANELLI M.S

PLANT PHYSIOLOGY AND BIOCHEMISTRY

ELSEVIER FRANCE-EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER

Lugar: Paris; Año: 2019 vol. 142 p. 519 - 527

0981-9428

Water deficit is one of the most serious environmental factors that affect the productivity of crops in the world.Arachis hypogaea is a legume with a high nutritional value and 70% is cultivated in semi-arid regions. Thisresearch aimed to study the effect of water deficit on peanut root exudates composition, analyzing the importanceof exudates on peanut-PGPR interaction under restrictive water condition.Peanut seedlings were subjected to six treatments: 0 and 15mM PEG, in combination with non-inoculated,Bradyrhizobium sp. and Bradyrhizobium-Azospirillum brasilense inoculated treatments. We analyzed the 7-daypeanut root exudate in response to a water restrictive condition and the presence of bacterial inocula. Molecularanalysis was performed by HPLC, UPLC and GC. Bacteria motility, chemotaxis, bacterial adhesion to peanutroots and peanut growth parameters were analyzed.Restrictive water condition modified the pattern of molecules exuded by roots, increasing the exudation ofNaringenin, oleic FA, citric and lactic acid, and stimulation the release of terpenes of known antioxidant andantimicrobial activity. The presence of microorganisms modified the composition of root exudates. Water deficitaffected the first events of peanut-PGPR interaction and the root exudates favored bacterial mobility, the chemotaxisand attachment of bacteria to peanut roots.Changes in the profile of molecules exuded by roots allowed A. hypogaea-Bradyrhizobium andA.hypogaea?Bradyrhizobium-Azospirillum interaction thus reversing the negative effects of restrictive watercondition on peanut growth. These findings have a future potential application to improve plant-PGPR interactionsunder water deficit by formulating inoculants containing key molecules exuded during stress.