INV1 — Nicotiana attenuata

Summary

A4A49_31418 (INV1) in Nicotiana attenuata encodes a protein with beta-fructofuranosidase and sucrose alpha-glucosidase activities, belonging to the glycosyl hydrolase family 32. This gene is associated with phloem loading and unloading, carbohydrate storage, nectar secretion, sucrose breakdown, and secondary metabolite biosynthesis. It has been linked to seed development, plant ovule development, leaf senescence, and syngamy. The encoded protein localizes to the apoplast, plant-type cell wall, and pollen tube. INV1 is associated with traits including leaf length, seed size, photosynthetic rate, respiration rate, and contents of phosphate, abscisic acid, and cytokinin. Reduced cell-wall invertase activity in this gene has been linked to loss of nectar secretion. Studies of related genes in other species link the family to fruit sweetness, grain size, starch content, and male sterility.