July 26, 2016
A discovery with the potential to control sprouting
A RIKEN CSRS, Osaka University and Kobe University collaborative research group have discovered two genes, PGA1 and PGA2, in potato plants that are involved in the synthesis of steroidal glycoalkaloids (SGAs) such as solanine. SGAs accumulate in potato sprouts and flowers and are toxic to humans and animals at high concentrations. Researchers also clarified that PGA2 encodes for a 22-hydroxylase that converts cholesterol to 22-hydroxycholesterol, while PGA1 encodes for a 26-hydroxylase that converts 22-hydroxycholesterol to 22- and 26-dihydroxycholesterol.
Researchers also found that SGA amounts were extremely low in genetically modified potatoes from plants with either suppressed PGA1 or PGA2 expression compared with the potatoes from non-modified plants. Unexpectedly, the PGA1- and PGA2–suppressed potatoes did not sprout even after storage, yet began to sprout after planting in soil.These results demonstrate that the suppression of PGA1 and PGA2 expression and gene editing to destroy genes could lead to the breeding of plants that produce non-poisonous, controllable-sprouting potatoes.
Plant Physiology doi: 10.1104/pp.16.00137
N. Umemoto, M. Nakayasu, K. Ohyama, M. Y-Yamashita, M. Mizutani, H. Seki, K. Saito, T. Muranaka,
"Two Cytochrome P450 Monooxygenases Catalyze Early Hydroxylation Steps in the Potato Steroid Glycoalkaloid Biosynthetic Pathway".
Naoyuki Umemoto; Senior Research Scientist
Kazuki Saito; Group Director
Metabolomics Research Group