Identification and expression analysis of HK (histidine kinase) family receptors in peanut (Fabaceae)

RODRIGUEZ-MELO, JOHAN STIBEN; IBAÑEZ FERNANDO; TONELLI MARÍA LAURA; FABRA ADRIANA

Córdoba

Conferencia; Nineth international conference of the Peanut Research Community. Advances in Arachis through Genomics and Biotechnology; 2017

Identification and expression analysis of HK (histidine kinase) family receptors in peanut (Fabaceae).J. S. Rodríguez-Melo1, F. Ibañez1, M. L. Tonelli1 & A. Fabra1Department of Natural Sciences. National University of Río Cuarto1Cytokinins are ubiquitous plant hormones and their signal is perceived by membrane-located histidine kinases-cytokinin receptors. This hormone plays a central role in the formation of nitrogen-fixing root nodule primordia following inoculation with rhizobia. The aim of this study was to identify the HK family receptors in peanut and analyse the HK1 expression patterns in cultivated peanut Arachis hypogaea after rhizobial inoculation. Homology search was conducted using PeanutDB and PeanutBase, which contain Arachis hypogaea ESTs and the genomic sequences of the wild ancestral diploid species Arachis duranensis and Arachis ipaënsis, respectively. We identified 6 predicted proteins from the wild ancestors and 3 from cultivated peanut Arachis hypogaea. Our sequence analysis showed that these proteins possess typical features of HK receptors like extracellular CHASE domain connected via a transmembrane α helix to HIS-KIN and intracellular RESPONSE-REG domains. qRT-PCR analysis at 0, 1, 8, 16 and 24 hours post-inoculation with a peanut symbiont Bradyrhzobium sp. SEMIA 6144 WT or a mutant strain unable to produce Nod factors was performed to assess the expression patterns of these receptors.