Callose metabolism genes in chickpea reveal vascular defense against fusarium wilt

Chickpea, serves as high protein pulse crop for vegetarian people, faces major field losses from biotic stress like Fusarium wilt. Wilt management through biotechnological interventions using next generation sequencing method like transcriptomics have shown potentials. Transcriptomic data provide differential expressed genes (DEGs)that gives insights into the molecular responses in resistance mechanism. In our previous work, transcriptomic analysis has revealed many upregulated DEGs that may be promising candidates for defense during early hours of fusarium infestation. In this study we have analyzed a group of genes that highlights the importance of callose metabolism in disease management. Specifically, callose synthases genes, including CaCalS5, CaCalS3, CaCalS9X1, and CaCalSS10 showed notable upregulation during infection in resistant genotype with the exception of CaCalS9X2andCaCalS7which were upregulated in susceptible genotype. We have determined effective callose synthase complex activity during Fusarium attack in early time points and found its vital role during defense. Additionally, differential expression of genes (Endoglucanase 24, and Endoglucanase 12) involved in callose degradation were found upregulated in susceptible genotype, emphasizing their role in xylem vessel clogging together with overgrowth of mycelia structures as shown in anatomical pictures obtained from scanning electron microscopy. Confocal microscopy using aniline dye confers the callose deposition and xylem vessel blocking.