Multiple bHLH/MYB-based protein complexes regulate proanthocyanidin biosynthesis in the herbage of Lotus spp

ESCARAY F.J.; VALERI M.C.; DAMIANI F.; RUIZ O.A.; CARRASCO SORLI, P.; PAOLOCCI F

PLANTA

SPRINGER

Lugar: Berlin; Año: 2024 vol. 259 p. 1 - 16

0032-0935

Summary•Proanthocyanidins (PAs) are flavonoids important in pastoral agricultural systems to improve animal production and reduce greenhouse gas emissions. However, the primary forage legumes grown in these systems do not contain substantial PAs in leaves. Additionally, no significant progress has been made in inducing PAs to agronomically valuable levels in the herbage of these species when PA regulators from model species were ectopically expressed.•By reasoning that building this trait requires a profound knowledge of PA regulators and their interplay in species naturally committed to accumulating these metabolites in the target organs, we compared the shoot transcriptomes of two Lotus species polymorphic for this trait to search for differentially expressed MYB and bHLH genes. •The expression of regulators found as above was then tested in Lotus interspecific hybrids and Lotus spp. with contrasting PA levels in the herbage. By this approach, novel MYB activators and MYB-bHLH-based complexes which transactivate the promoters of the critical structural genes of PAs have been identified. •Overall, by employing Lotus as a model genus, we refined the transcriptional network underlying PA biosynthesis in the herbage of legumes. These findings are crucial to engineering this trait in other pastures.