Gene Expression, Histology and Histochemistry in the Interaction between Musa sp. and Pseudocercospora fijiensis

Abstract

Bananas are the main fruits responsible for feeding more than 500 million people in tropical and subtropical countries. Black Sigatoka, caused by the fungus Pseudocercospora fijiensis, is one of the most destructive disease for the crop. This fungus is mainly controlled with the use of fungicides; however, in addition to being harmful to human health, they are associated with a high cost. The development of resistant cultivars through crosses of susceptible commercial cultivars is one of the main focuses of banana breeding programs worldwide. Thus, the objective of the present study was to investigate the interaction between Musa sp. and P. fijiensis through the relative expression of candidate genes involved in the defence response to black Sigatoka in four contrasting genotypes (resistant: Calcutta 4 and Krasan Saichon; susceptible: Grand Naine and Akondro Mainty) using quantitative real-time PCR (RT–qPCR) in addition to histological and histochemical analyses to verify the defence mechanisms activated during the interaction. Differentially expressed genes (DEGs) related to the jasmonic acid and ethylene signalling pathway, GDSL-like lipases and pathogenesis-related proteins (PR-4), were identified. The number and distance between stomata were directly related to the resistance/susceptibility of each genotype. Histochemical tests showed the production of phenolic compounds and callosis as defence mechanisms activated by the resistant genotypes during the interaction process. Scanning electron microscopy (SEM) showed pathogenic structures on the leaf surface in addition to calcium oxalate crystals. The resistant genotype Krasan Saichon stood out in the analyses and has potential for use in breeding programs for resistance to black Sigatoka in banana and plantains.

Acta Physiologiae Plantarum Histochemistry and Gene Expression Using Glycerol in the Pathosystem Musa X Mycosphaerella Fijiensis

“…The detection of callose in the rst days after inoculation indicates that the application of Glycerol led to a tendency to condition the plant to a state of resistance to fungal attack. Soares et al (2022) did not identify the presence of callose in banana plants in susceptible genotypes Grande Naine and Akondro Mainty infected with Black Sigatoka, evaluated up to 21 Dai.…”

“…It has been scienti cally proven that the higher the density of stomata, where the fungus M. jiensis infects the plant, the greater the infection. Grande Naine, a susceptible genotype, has a high density of stomata, which facilitates the penetration of the fungus (SOARES et al, 2022). The plant, with physical and chemical defense responses, uses mechanisms to try to defend itself from the invader.…”

Banana Plant Waste Rotary Dryer Design and Simulation Using 3D Computer Aided Design

“…Phenolic compounds in bananas were found to have functional properties, inhibiting lipid oxidation and microbial growth, potentially contributing to health benefits such as reduced cancer and heart disease risk [4]. In 2020, global fruit production was projected to reach a million metric tons, with bananas contributing significantly [2].…”