Abstract

A cDNA clone for a receptor-like protein kinase gene (WELP1) was obtained from wheat. The clone is 3286 bp long with an open reading frame of 2734 bp long encoding a 977 amino acids containing single peptide. This deduced peptide contains four distinctive domains characteristic of receptor kinases: (1) a putative amino terminal signal sequence domain; (2) a domain with eighteen extracellular leucine-rich repeat sequences; (3) a membrane-spanning domain; and (4) a cytoplasmic protein kinase domain that contains 11 sub-domains conserved among protein kinases. WELP1 gene is expressed in glume, rataria, stem and anther. 1.7 kb upstream sequences of WELP1 were isolated and analyzed. Many cis-elements that respond to environment stimuli were found. Correspondingly, expression of WELP1 is rapidly induced by several environmental stresses such as dehydration, high salt and high temperature. A WELP1::hGFP fusion protein was found to be localized in the plasma membrane upon introduction into epidermal onion cells, suggesting that the WELP1 gene encodes a membrane protein that perceives general stress signals. Therefore, WELP1 can be a candidate gene for biotechnology engineer to improve plant abiotic stress tolerance.

Key words:  ERECTA protein, promoter, sub-cellular localization, induced mechanism.

Abbreviation

WUE, water use efficiency; LRR-RLKs, leucine-rich repeat receptor-like kinases; RT-PCR, reverse transcription-polymerase chain reaction; QTL, quantitative trait locus; eQTL, expression quantitative trait locus; RACE, rapid amplification of cDNA ends; ABA, abscisic acid; GA, gibberellin acid.