Historial Account: Duckweeds, photosynthesis and ethylene

Authors: Mattoo, Autar

Submitted to: Duckweed Forum
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/8/2020
Publication Date: 7/22/2020
Citation: Mattoo, A.K. 2020. Historial Account: Duckweeds, photosynthesis and ethylene. Duckweed Forum. 8(3):56-93.

Interpretive Summary: Duckweeds are classified as aquatic plants and research using them as a model has now revealed their nutritional quality. The genomes of a few duckweeds have recently been discerned. Many academicians and the food industry are interested in the nutritional aspects of duckweeds. We are using duckweed as a model to answer biological questions related to nutrition and hormone biology. This is an invited article by the publishers of Duckweed Forum to provide a review of the literature created in this field by the USDA scientist and how it happened. This review highlights the potential of duckweeds in delineating metabolic pathways and regulation that was critical in understanding the dynamics of key regulators of photosystem II and photosynthesis. This historical research is of interest to plant physiologists, scientists, and genetic experts.

Technical Abstract: Aquatic higher plants have been used as biological/biochemical models since a long time to address important biological questions in addition to some of them becoming a medium for purifying wastewater (Oron et al., 1985; Edelman et al., 2018). One such aquatic plant group is called duckweeds, which are classified within the family of Lemnaceae. In recent years, research using duckweeds has intensified basically because of their value as nutritious food for human consumption. Duckweeds, Landoltia punctata in particular, have the advantage of simple growth conditions, relatively short doubling time, aseptic cultivation, easy uptake of solutes including radiolabeled molecules, amenable to dissection, easy handling, and well suited for studying plant biology. We utilized Landoltia punctata as a model system to study the biology of a rapidly synthesized thylakoid protein named D1 photosystem II reaction center protein. The aquatic duckweed model (e.g., Landoltia punctata) is not only amenable for quick uptake of nutrients from a water body or the exogenously supplied radiolabeled compounds, the clear resolution of the fractionated samples on gels was found remarkable. It was found that duckweeds produce the hormone ethylene in response to cupric ions by a biosynthetic route different than shown in terrestrial plants.