PHOSPHATIDYLINOSITOL 3-KINASE AT THE VERY EARLY 2 SYMBIONT PERCEPTION: A LOCAL NODULATION CONTROL UNDER 3 STRESS CONDITIONS?

GERMÁN ROBERT1,2, NACIRA MUÑOZ, LASCANO RAMIRO; XOCHITL ALVARADO-AFFANTRANGER, ; VANINA DAVIDENCO; LAURA SAAVEDRA; MARGARITA RODRÍGUEZ-KESSLER, GEORGINA ESTRADA-NAVARRETE3, FEDERICO SÁNCHEZ,; RAMIRO LASCANO; LASCANO RAMIRO

JOURNAL OF EXPERIMENTAL BOTANY

OXFORD UNIV PRESS

Lugar: Oxford; Año: 2018 p. 2037 - 2048

0022-0957

ABSTRACT103 Root hair curling is the early and essential morphological change for the104 success of the symbiotic interaction between legumes and rhizobia. At this105 stage rhizobia grow as infection thread within root hairs and are internalized into106 the plant cells via endocytosis, where PI3K enzyme plays important roles.107 Former studies of our group showed that stress conditions affect previous108 stages of the symbiotic interaction, from 2 to 30 min post-inoculation, which we109 call as very early host-responses, and affect symbiosis establishment. Herein,110 we demonstrated the relevance of the very early host-responses for the111 symbiotic interaction, where PI3K and NADPH oxidase complex have key roles112 in the microsymbiont-recognition response modulating the apoplastic and113 intracellular/endosomal ROS induction in root hairs. Interestingly, comparing114 with soybean mutant plants that do not perceive the symbiont, we demonstrated115 that the very early symbiont-perception under sublethal saline stress conditions116 induced root hairs death. Together, these results highlight not only the117 relevance of the very early host-responses on later stages of the symbiont118 interaction, but also postulate them as a mechanism for the local control of the119 nodulation capacity, prior to the abortion of infection thread, preventing the120 allocation of resources/energy for nodules formation under unfavorable121 environmental conditions.