Influences of Ipomoea batatas Anti-Cancer Peptide on Tomato Defense Genes

This study investigates the impact of IbACP (Ipomoea batatas anti-cancer peptide) on defense-related gene expression in tomato leaves, focusing on its role in plant defense mechanisms.

Previously, IbACP was isolated from sweet potato leaves, and it was identified as a peptide capable of inducing an alkalinization response in tomato suspension culture media. Additionally, IbACP was found to regulate the proliferation of human pancreatic adenocarcinoma cells.

Elucidate IbACP's molecular influence on defense-related gene expression in tomato leaves using next-generation sequencing analysis.

To assess the impact of IbACP on defense-related gene expression, transcriptome data were analyzed, encompassing various functional categories such as photosynthesis, metabolic processes, and plant defense. Semi-quantitative reverse-transcription polymerase chain reaction analysis was employed to verify transcription levels of defense-related genes in tomato leaves treated with IbACP for durations ranging from 0 h (control) to 24 h.

IbACP induced jasmonic acid-related genes (LoxD and AOS) at 2 h, with a significant up-regulation of salicylic acid-dependent gene NPR1 at 24 h. This suggested a temporal antagonistic effect between jasmonic acid and salicylic acid during the early hours of IbACP treatment. Downstream ethylene-responsive regulator genes (ACO1, ETR4, and ERF1) were consistently down-regulated by IbACP at all times. Additionally, IbACP significantly up-regulated the gene expressions of suberization-associated anionic peroxidases (TMP1 and TAP2) at all time points, indicating enhanced suberization of the plant cell wall to prevent pathogen invasion.

IbACP enhances the synthesis of defense hormones and up-regulates downstream defense genes, improving the plant's resistance to biotic stresses.