Accelerating quinoa breeding through site-directed genotype screening reveals TSARL1 as a key regulator of saponin biosynthesis in quinoa seeds

Beskrivelse

Climate change may result in a drier climate and increased salinization, threatening agricultural productivity worldwide. Quinoa (Chenopodium quinoa) produces highly nutritious seeds and tolerates abiotic stresses such as drought and high salinity, making it a promising future food source. However, the presence of antinutritional saponins in their seeds is an undesirable trait. We mapped genes controlling seed saponin content to a genomic region that includes the gene encoding the transcription factor TSARL1. We isolated desired genetic variation in TSARL1 by producing a large mutant library of a commercial quinoa cultivar and screening the library for specific nucleotide substitutions using droplet digital PCR. We were able to isolate two independent tsarl1 mutants, which retained saponins in the leaves and roots for defence, but saponins were undetectable in the seed coat. By conducting comprehensive RNA-seq and proteomic analyses we could show that TSARL1 specifically controls seed saponin biosynthesis in the committed step after 2,3-oxidosqualene. In addition, our study led to the identification of novel genes that encode cytochrome P450s, UDP-glucuronosyltransferases (UGTs), cellulose-synthase superfamily-derived glycosyltransferases, and transporters putatively involved in TSARL1-mediated saponin biosynthesis. Together, our findings offer valuable insights into the function of TSARL1 and represent a significant breakthrough for quinoa breeding. This knowledge can facilitate the development of quinoa varieties with reduced saponin content, thereby improving its suitability as a future food source in the face of climate change.

Periode	21 aug. 2024 → 23 aug. 2024
Begivenhedstitel	CPSC conference: Translational agriculture - from model plants to crops
Begivenhedstype	Konference
Placering	Frederiksberg C, DanmarkVis på kort
Grad af anerkendelse	International