Transcriptomic profiling of Lathyrus sativus L. metabolism of ß-ODAP, a neuroexcitatory amino acid associated with neurodegenerative lower limb paralysis

Authors: XU, QUANLE - Northwest A&f University; LIU, FENGJUAN - Northwest A&f University; QU, RUIHONG - Northwest A&f University; Gillman, Jason; BI, CHUNXIAO - Northwest A&f University; HU, XIN - Northwest A&f University; CHEN, PENG - Northwest A&f University; Krishnan, Hari

Submitted to: Plant Molecular Biology Reporter
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/14/2018
Publication Date: 11/24/2018
Citation: Xu, Q., Liu, F., Qu, R., Gillman, J.D., Bi, C., Hu, X., Chen, P., Krishnan, H.B. 2018. Transcriptomic profiling of Lathyrus sativus L. metabolism of ß-ODAP, a neuroexcitatory amino acid associated with neurodegenerative lower limb paralysis. Plant Molecular Biology Reporter. 36(5-6):832-843. https://doi.org/10.1007/s11105-018-1123-x.
DOI: https://doi.org/10.1007/s11105-018-1123-x

Interpretive Summary: Grass pea is a very important legume crop for arid and semiarid regions, due to its remarkable tolerance/resistance to several distinct biotic and abiotic stresses. Like soybean, grass pea seeds are rich in protein and can serve as an inexpensive, highly nutritious, and well-balanced source of human dietary protein. The seed proteins of soybean and grass pea are similar. Despite these advantages, grass pea has not achieved the widespread acceptance of other legume species, in large part due to the presence of a toxin (ß-ODAP) which is responsible for neurodegenerative lower limb paralysis disease called lathyrism. In this study, we investigated changes in ß-ODAP gene expression during grass pea seed germination. Our results provide comprehensive gene expression profiles during the period of ß-ODAP accumulation and degradation. Results from our study will be invaluable to plant breeders and biotechnologists to develop legumes that are devoid of toxins so that we can improve the overall quality of legume seed proteins. Superior quality legume proteins can be utilized to meet the nutritional requirements of the multitude of malnourished people around the world.

Technical Abstract: Grass pea (Lathyrus sativus L.) is a unique potential crop for marginal arid regions with untapped, exceptional biotic/abiotic stress tolerance and high protein content seeds. High dietary intake of grass pea is associated with neurodegenerative lower limb paralysis, thought to be due to the compound ß-N-oxalyl-L-a, ß-diaminopropionic acid (ß-ODAP). ß-ODAP increases after seed germination and then decreases subsequently. To monitor changes in gene expression during seed germination RNA sequencing was performed on seedlings at 2, 6, and 25 days after sowing. A total of 213,258 unigenes were detected, corresponding to 39,548 coding sequences. Extensive Gene Ontology and co-expression network analysis suggested that primary metabolism, particularly carbohydrates and sulfur, were correlated with ß-ODAP content. Our results identified transcriptional profiles related to grass pea seedling development, and provide invaluable insight into mechanisms of ß-ODAP accumulation and degradation. Defining the gene space is essential for intelligent genetic, biotechnological and breeding to reduce ß-ODAP for human benefit.