Konjac Glucomannan Oligosaccharides (KGMOS) Confers Innate Immunity against <i>Phytophthora nicotianae</i> in Tobacco

oleh: Md Mijanur Rahman Rajib, Kuikui Li, Md Saikat Hossain Bhuiyan, Wenxia Wang, Jin Gao, Heng Yin

Format: Article
Diterbitkan: MDPI AG 2024-08-01

Deskripsi

In this study, KGMOS (DP, 2-13), derived from KGM (Konjac glucomannan), was applied to elucidate plant immunity in a <i>Nicotiana benthamiana Phytophthora nicotianae</i> model. Application of KGMOS (25–100 mg/L) notably inhibited <i>P. nicotianae</i>, resulting in reduced disease indices and a significant accumulation of defense molecules such as H<sub>2</sub>O<sub>2</sub> and callose. Transcriptomic analysis revealed that genes shared between KGMOS-treated and control plants are involved in signaling pathways, transcription regulation, hydrogen peroxide catabolism, and oxidative stress response. This suggests that KGMOS triggers H<sub>2</sub>O<sub>2</sub> accumulation, callose deposition, and activation of the salicylic acid (SA) and jasmonic acid/ethylene (JA/ET) pathways after pathogen inoculation. Upregulated defense-response genes in the KGMOS group included SA-related late blight-resistant, pathogenesis-related (<i>PR</i>), and JA/ET-related ethylene response factor (<i>ERF</i>) genes. Heatmap analysis showed more upregulated defense genes (<i>PR</i> and <i>NPR</i>) related to SA in the KGMOS-treated group than in controls. RT-qPCR validation revealed significant upregulation of SA and JA/ET pathway genes in KGMOS-treated plants. Higher SA content in these plants suggests enhanced disease resistance. This study concludes that KGMOS pre-treatment induced resistance against <i>P. nicotianae</i>, especially at a lower concentration (25 mg/L). These findings could offer valuable insights for the future application of KGMOS in controlling plant diseases for sustainable agriculture and postharvest management.