Vacuolar Processing Enzymes Modulating Susceptibility Response to Fusarium oxysporum f. sp. cubense Tropical Race 4 Infections in Banana

Abstract

Fusarium oxysporum f. sp. cubense tropical race 4 (FocTR4) is a destructive necrotrophic fungal pathogen afflicting global banana production. Infection process involves the activation of programmed cell death (PCD). In this study, seven Musa acuminata vacuolar processing enzyme (MaVPE1–MaVPE7) genes associated with PCD were successfully identified. Phylogenetic analysis and tissue-specific expression categorized these MaVPEs into the seed and vegetative types. FocTR4 infection induced the majority of MaVPE expressions in the susceptible cultivar “Berangan” as compared to the resistant cultivar “Jari Buaya.” Consistently, upon FocTR4 infection, high caspase-1 activity was detected in the susceptible cultivar, while low level of caspase-1 activity was recorded in the resistant cultivar. Furthermore, inhibition of MaVPE activities via caspase-1 inhibitor in the susceptible cultivar reduced tonoplast rupture, decreased lesion formation, and enhanced stress tolerance against FocTR4 infection. Additionally, the Arabidopsis VPE-null mutant exhibited higher tolerance to FocTR4 infection, indicated by reduced sporulation rate, low levels of H2O2 content, and high levels of cell viability. Comparative proteomic profiling analysis revealed increase in the abundance of cysteine proteinase in the inoculated susceptible cultivar, as opposed to cysteine proteinase inhibitors in the resistant cultivar. In conclusion, the increase in vacuolar processing enzyme (VPE)-mediated PCD played a crucial role in modulating susceptibility response during compatible interaction, which facilitated FocTR4 colonization in the host.

λ-Carrageenan promotes plant growth in banana via enhancement of cellular metabolism, nutrient uptake, and cellular homeostasis

“…The resulting cDNA was analysed by qRT-PCR using QuantiNova SYBR Green PCR Kit (Qiagen, Germany) in Bio-rad CFX 96™ thermal cycler (Bio-Rad, USA) following the protocol described by Kamarudin et al 50 . The housekeeping glyceraldehyde 3-phosphate dehydrogenase ( gapdh ) and ubiquitin ( ubq ) genes were used as reference genes 51 . The data was analysed using Bio-rad CFX Manager™ software.…”

Promoter Cis-Element Analyses Reveal the Function of αVPE in Drought Stress Response of Arabidopsis

“…Total RNA was isolated via RNeasy Plant Mini Kit (Qiagen, Hilden, Germany) following the protocol described in [ 14 ]. First-strand cDNA was converted from 1 μg of the isolated total RNA using QuantiNova Reverse Transcription Kit (Qiagen, Germany).…”

Vacuolar Processing Enzymes in Plant Programmed Cell Death and Autophagy

“…These ultrastructural analyses have shown the contribution of VPEs to vacuole collapse during PCD [ 35 ]. Further research has shown that VPEs are involved in plant defense against such pathogens as the bacterium Erwinia amylovora [ 62 ], nematode Heterodera filipjevi [ 63 ], the oomycetes Hyaloperonospora arabidopsidis [ 64 ] and Phytophthora parasitica [ 65 ], and the fungi Phaeoisariopsis personata [ 66 ], Fusarium oxysporum (FocTR4) [ 67 ] and Botryosphaeria dothidea [ 68 ].…”