HvPap-1 is a barley protease induced by the attack of both, an acari and a fungus. However, when it is overexpressed or silenced opposite effects against both stresses are found.
C1A cysteine proteases are the most abundant enzymes responsible for the proteolytic activity during different processes like germination, development and senescence in plants. To identify and characterize C1A cysteine proteases of barley with a potential role in defense, mRNA and protein expression patterns were analyzed in response to biotics stresses. HvPap-1 was particularly induced by flagellin or chitosan elicitation, and biotic stresses such as the phytopathogenic fungusMagnaporthe oryzae or the phytophagous mite Tetranychus urticae. To elucidate the in vivo participation of this enzyme in defense, transformed barley plants overexpressing or silencing HvPap-1 encoding gene were subjected to M. oryzae infection or T. urticae infestation. Whereas overexpressing plants were less susceptible to the fungus than silencing plants, the opposite behavior occurred to the mite. This unexpected result highlights the complexity of the regulatory events leading to the response to a particular biotic stress.
Diaz-Mendoza, M; Velasco-Arroyo, B; Santamaria, ME; Diaz, I; Martinez, M. 2017. "HvPap-1 C1A protease participates differentially in the barley response to a pathogen and an herbivore". Frontiers in Plant Science. DOI: 10.3389/fpls.2017.01585".