Abstract:Guava variants are abundant and fruit texture varies considerably between varieties. The softening degree of fruit determines its edible taste, transportation, storage and shelf life and other commodity values. In order to explore the regulatory genes affecting the texture softening of guava fruit, transcriptomic sequencing was performed on two cultivars,Fenhongmi(crisp)and Xigua No.2(soft)at the firm ripening stage and soft ripening stage. The results showed that the number of differentially expressed genes was the highest among two varieties at soft maturity stage. GO annotation showed that differentially expressed genes were mainly enriched in molecular functions such as binding activity and catalytic activity, and KEGG metabolic pathway analysis showed that differentially expressed genes were mainly enriched in photosynthesis, photosynthetic antenna protein, galactose metabolism and plant hormone signal transduction pathways. The difference of texture of the two varieties in soft ripening stage is closely related to the regulation of cell wall metabolism, lignin biosynthesis pathway, plant hormone metabolism genes and transcription factors. The up-regulated expression of J3R85008159-PG and J3R85010291-XTH is an important factor promoting the softening of guava. J3R85010291-TCH4 may regulate fruit softening by reducing the mechanical strength of cell wall. Down-regulated expression of lignin synthesis pathway genes (J3R8506005-CAD, J3R8502863-POD, J3R8507303-POD, J3R8500836-LAC and J3R8507803-LAC) delayed lignin accumulation and promoted fruit softening. ABA pathway regulatory genes (PYL and SNRK2), ethylene pathway regulatory genes (ETR/ ERS, EBF1/2, EIN3) and related transcription factors (MYB, NAC, ERF, BHLH and WRKY) may synergistic regulate the expression of cell wall metabolic genes and thus affect the softening process of guava.