Importance of Cell Wall Permeability and Cell Wall Degrading Enzymes during Infection of <i>Botrytis cinerea</i> in Hazelnut

Abstract

The Botrytis bunch mold, Botrytis cinerea pathogen is a necrotrophic ascomycete that infects hundreds of plant species, including hazelnut. B. cinerea produces toxins that induce cell wall degrading enzymes. In the current research work, we used eight hazelnut varieties and recorded their resistance levels in response to B. cinerea infection. Results showed that different varieties respond differently to B. cinerea infection. Disease index analysis revealed the resistance level of eight hazelnut varieties in the order of DW > OZ > L3 > PZ > XD1 > YZ > L1 > QX. Moreover, cell membrane permeability as well as the activities of cell wall degrading enzymes were measured. The increased level of cell wall degrading enzymes facilitates the fungal pathogens’ ability to colonize plants and cause infection. According to the results obtained through enzyme analysis, the hazelnut varieties L1 and QX, which were proved to be highly susceptible against B. cinerea, had the highest cell wall degrading enzyme production. DW and OZ, which were revealed to be resistant varieties through disease index data, also showed relatively lower activity of degrading enzymes as compared to other varieties. Our comparison analysis between the disease index and enzyme production confirms that disease occurrence and plant susceptibility strongly depend upon cell wall permeability. Our enzyme activity results validated the resistance order revealed by disease index assessment results (DW > OZ > L3 > PZ > XD1 > YZ > L1 > QX), and varieties DW and OZ were found to be the most resistant, while QX and L1 were found to be the most susceptible varieties against B. cinerea infection. Our study lays the foundation to further explore other factors involved in grey mold resistance in hazelnut.

Keywords

• <i>Botrytis cinerea</i>
• hazelnut
• grey mold
• resistance
• enzymes