Identification of Kunitz-Type Inhibitor Gene Family of Reveals a Stress Tolerance Function in Inverted Cuttings.

Plant protease inhibitors are a ubiquitous feature of plant species and exert a substantial influence on plant stress responses. However, the (Kunitz trypsin inhibitor) family responding to abiotic stress has not been fully characterized in . In this study, we conducted a genome-wide study of the family and analyzed their gene structure, gene duplication, conserved motifs, cis-acting elements, and response to stress treatment. A total of 29 s were identified in the genome. Based on phylogenetic analysis, the Pys were divided into four groups (1,2, 3, and 4). Promoter sequence analysis showed that the Pys contain many cis-acting elements related to light, plant growth, hormone, and stress responses, indicating that Pys are widely involved in various biological regulatory processes. RNA sequencing and real-time quantitative polymerase chain reaction analysis showed that genes were differentially expressed under the inverted cutting stress of . Transcriptome analysis of leaves revealed that , , and were highly upregulated after inverted cutting. Through the GEO query of data, genes played a positive defense role in MeJa, drought, time series, and pathogen stress. This study provided comprehensive information for the family in , which should be helpful for the functional characterization of genes in the future.