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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Sustainable Agricultural Systems Laboratory » Research » Publications at this Location » Publication #378370
Research Project: Molecular Understanding of the Nexus between Plant Bioregulators, Stress Tolerance, and Nutrient Content in Plants

Location: Sustainable Agricultural Systems Laboratory

Title: Identification, phylogeny,and comparative expression of the lipoxygenase gene family of the aquatic duckweed, Spirodela polyrhiza, during growth and in response to methyl jasmonate and salt

Author
item UPADHYAY, RAKESH - Purdue University
item EDELMAN, MARVIN - Weizmann Institite Of Science
item Mattoo, Autar

Submitted to: International Journal of Molecular Sciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/11/2020
Publication Date: 12/15/2020
Citation: Upadhyay, R.K., Edelman, M., Mattoo, A.K. 2020. Identification, phylogeny,and comparative expression of the lipoxygenase gene family of the aquatic duckweed, Spirodela polyrhiza, during growth and in response to methyl jasmonate and salt. International Journal of Molecular Sciences. 21(24):9527. https://doi.org/10.3390/ijms21249527.
DOI: https://doi.org/10.3390/ijms21249527

Interpretive Summary: Duckweed has emerged as an important nutrition-rich aquatic sustainable crop plant. Duckweed biomass doubles almost daily under optimal conditions in nature or in the laboratory. In plant biology, among other studies, duckweeds have been used as a model to study nutritional enhancement and photosynthesis dynamics. Jasmonic acid/methyl jasmonate (JAS/meJAS) are collectively called oxylipins synthesized via the lipoxygenase gene (LOX) pathway. Here, we identified the complete set of LOX gene families in duckweed Spirodela polyrhiza and studied their dynamics during growth and in response to the oxylipin MeJAS. There is a keen biotech interest in duckweeds as an unexploited source of high-quality protein to supplement the food for the growing world population. This novel study provides important information about lipoxygenase gene family in duckweeds which is of importance for biomass production and of interest to scientists, plant physiologists and genomic experts.

Technical Abstract: Lipoxygenases (LOXs) (EC 1.13.11.12) catalyze the oxygenation of fatty acids and produce oxylipins, including the plant hormone jasmonic acid (JA) and its methyl ester, methyl jasmonate (MeJA). Little information is available about the LOX gene family in aquatic plants such as duckweeds. We identified a novel LOX gene family comprising nine LOX genes in the greater duckweed Spirodela polyrhiza. Reduced size of duckweeds has not led to a reduction in LOX family genes. The 13-LOX subfamily, with 7 genes, predominated while the 9-LOX subfamily with 2 genes, reduced, an opposite trend from known LOX families of other plant species. Predominance of the 13-LOX subfamily in the Spirodela genome suggests a higher requirement of JA/MeJA. All of the Spirodela LOX genes identified were expressed to different degrees, with LOX1, 6, 7, 8 and 9 expressed at a higher level than LOX2, 3, 4 and 5. Quantitative transcript abundance of LOX gene family members within the Spirodela genus (Sp7498 and Sp7003 strains) as a function of growth is also presented. Albeit, two tandem duplicated group LOX genes showed redundancy in their expression patterns. Further, compared to Spirodela, the LOX genes of other duckweed genera - Lemna minor (Lm8627) and Landoltia punctata (Lp5562) were expressed at a very low degree except for Lemna LOX1 which was expressed to a high degree. JA/MeJA-based feedback regulation involving activation of specific members of the Spirodela LOX genes is also highlighted.