Lathyrus sativus mRNA SMRTseq

Grass pea (Lathyrus sativus L.) is a grain legume commonly grown in parts of Asia and Africa for human and animal consumption. While being a highly nutritious and robust crop, able to survive both drought and floods, it also produces a neurotoxic compound, b-N-oxalyl-L-a,b-diaminopropionic acid (b-ODAP), which can cause a severe neurological disorder if consumed as a main diet component. So far, the enzyme that catalyzes the formation of b-ODAP has not been identified. By combining protein purification and enzymatic assays with transcriptomic and proteomic analyses, we identified the enzyme b-ODAP synthetase (BOS) from L. sativus. We show that BOS is a HXXXD-type acyltransferase of the BAHD superfamily and that its crystal structure is highly similar to that of plant hydroxycinnamoyl transferases. The identification of BOS, more than 50 years following its discovery, opens the way towards the generation of non-toxic grass pea cultivars for safe human consumption.