Heterologous expression of the Glycine soja Kunitz-type protease inhibitor GsKTI improves resistance to drought stress and Helicoverpa armigera in transgenic Arabidopsis lines

Kunitz-like protease inhibitors (KTIs) have been identified to play critical roles in insect defense, but evidence for their involvement in drought stress is sparse. The aim of this study was to identify and functionally characterize a Kunitz-like protease inhibitor, GsKTI, from the wild soybean (Glycine soja) variety ED059. Expression patterns suggest that drought stress and insect herbivory may induce GsKTI transcript levels. Transgenic Arabidopsis lines overexpressing GsKTI have been shown to exhibit enhanced drought tolerance by regulating the ABA signaling pathway and increasing xylem cell number. Transgenic Arabidopsis leaves overexpressing GsKTI interfered with insect digestion and thus had a negative effect on the growth of Helicoverpa armigera. It is concluded that GsKTI increases resistance to drought stress and insect attack in transgenic Arabidopsis lines. •This study identifies and characterizes the GsKTI gene from the strongly cotton bollworm-resistant wild soybean ED059.•The study investigated the subcellular localization and expression pattern of GsKTI in response to various stresses.•The study found that GsKTI positively regulates drought and cotton bollworm resistance in Arabidopsis.•The GsKTI overexpression Arabidopsis results in insect resistance by severely impairing the immune system of cotton bollworm larvae.