sentence: The present study builds on these data by demonstrating that CaHSL1 , encoding an RD RLK , is target by CaWRKY40 and the CaHSL1 protein acts as a positive regulator in pepper basal and acquired thermotolerance under high humidity ; however , CaHSL1 differs from CaWRKY40 in its role during the response of pepper to RSI.The deduced amino-acid sequence of CaHSL1 shares domain-structure similarity with RLKs and high sequence similarity with putative HSLs from other plant species ; it also contains a conserved arginine-aspartic acid motif in its S_TKc domain , thus suggesting that CaHSL1 belongs to the RD RLKs in pepper .