Deciphering Alkaloid Bitter Compounds and Relevant Transcription Factors in Papaya

, associated with alkaloid biosynthesis. Finally, using single-nucleus RNA sequencing technology, we constructed a comprehensive gene expression atlas of papaya fibrous strands and stems, successfully identifying multiple cell types, including epidermal cells, guard cells, parenchyma cells, and phloem cells. Epidermal and phloem cells serve as the primary sites of alkaloid metabolism in papaya. These findings provide new insights into the molecular mechanisms of bitterness in papaya's fibrous strands and yield genomic resources for improving fruit quality in papaya.