Transcriptomics-based analysis of the effect of herbal extracts on soft rot kiwi disease control

The experiment was divided into 4 groups, A (CHEC+good fruit), B (good fruit, control), C (CHEC + diseased fruit), D diseased fruit (Botryosphaeria dothidea and Diaporthe phaseolorum infecting kiwifruit fruit). The results of the fruit storage experiment showed that the good fruit percentage in group A still reached 86%, 70% in group C, and only 6% in group D on the 80^th day of storage. Transcriptomics experiments showed (at 28 days of fruit storage, when diseased fruit started to appear rapidly in group D) that 18,337 transcripts in group A, 18,783 transcripts in group B, 18,758 transcripts in group C, and 16,354 transcripts in group D. Group D had the lowest number of genes, mainly due to the degradation of genes after fruit infestation by pathogenic fungi. The enrichment results of GO showed that the metabolic processes closely associated with fruit softening (top 20 in terms of enrichment) were polysaccharide metabolic process, carbohydrate catabolic process, carbohydrate metabolic process, polysaccharide catabolic process. In the case of groups C and D (pectin degradation metabolism), 13 transcripts were upregulated and 5 were downregulated in pectinesterase, 8 transcripts were upregulated and 3 were downregulated in pectate lyase, and 3 transcripts were upregulated and 1 was downregulated in polygalacturonase. In groups C and D (starch degradation metabolic process), 5 transcripts were upregulated and 2 downregulated in 1,4-alpha-glucan branching enzyme, 3 transcripts were upregulated and 1 downregulated in isoamylase, 3 transcripts were upregulated and 1 downregulated in alpha-amylase, and 9 transcripts were upregulated and 2 downregulated in beta-amylase. In summary, herbal extracts can effectively reduce fruit softening and spoilage by decreasing the activity of cell wall metabolizing enzymes in diseased fruits.