Growth and Nutritional Quality of Lemnaceae Viewed Comparatively in an Ecological and Evolutionary Context

Abstract

This review focuses on recently characterized traits of the aquatic floating plant Lemna with an emphasis on its capacity to combine rapid growth with the accumulation of high levels of the essential human micronutrient zeaxanthin due to an unusual pigment composition not seen in other fast-growing plants. In addition, Lemna’s response to elevated CO2 was evaluated in the context of the source–sink balance between plant sugar production and consumption. These and other traits of Lemnaceae are compared with those of other floating aquatic plants as well as terrestrial plants adapted to different environments. It was concluded that the unique features of aquatic plants reflect adaptations to the freshwater environment, including rapid growth, high productivity, and exceptionally strong accumulation of high-quality vegetative storage protein and human antioxidant micronutrients. It was further concluded that the insensitivity of growth rate to environmental conditions and plant source–sink imbalance may allow duckweeds to take advantage of elevated atmospheric CO2 levels via particularly strong stimulation of biomass production and only minor declines in the growth of new tissue. It is proposed that declines in nutritional quality under elevated CO2 (due to regulatory adjustments in photosynthetic metabolism) may be mitigated by plant–microbe interaction, for which duckweeds have a high propensity.

DNA barcoding and biomass accumulation rates of native Iranian duckweed species for biotechnological applications

“…Duckweed is described as one of the fastest angiosperms due to its ability to double its biomass in a short time period. Demmig-Adams et al (2022) suggest that the rapid growth of duckweed, even under limited light conditions, may be related to relatively thin photosynthetic organs (fronds) without complex structures on the water surface, allowing all chloroplasts to be involved in sugar production. The free-floating fronds with high availability of nutrient resources have higher photosynthetic yields.…”

Species- and Metal-Specific Responses of the Ionome of Three Duckweed Species under Chromate and Nickel Treatments

“…Another consideration for bioremediation applications is that duckweeds are highly plastic plants that will respond to environmental stimuli by rapid phenotypic modulation. In response to changing ambient conditions, duckweeds can acclimate by altering e.g., the frond size or the concentration and ratio of photosynthetic pigments [ 18 , 19 ]. A typical plant response to suboptimal conditions is the increase of dry matter content and leaf (in case of duckweeds frond) mass-to-area ratio (LMA) [ 20 , 21 , 22 ].…”

Productivity and Nutrient Quality of Lemna minor as Affected by Microbiome, CO2 Level, and Nutrient Supply

“…The resulting excessively high source-to-sink ratio can trigger feedback downregulation of photosynthesis, slow carbohydrate production [14], and accelerate onset of plant senescence [15][16][17]. Specifically, foliar carbohydrate build-up leads to a back-up of electrons in the photosynthetic electron transport chain and subsequent electron transfer to oxygen that results in production of reactive oxygen species (ROS) [18].…”

“…For example, chlorophyll-binding proteins also bind several carotenoids that serve as essential human micronutrients. These carotenoids include provitamin A (β-carotene) as well as lutein and the xanthophyll cycle pool, a set of rapidly inter-convertible xanthophylls that produce zeaxanthin under exposure to excess light [18]. Carotenoids are an important part of plant nutritional quality because they serve as essential human micronutrients needed to support human vision, immune health, and cognitive performance [28][29][30][31].…”

“…Carotenoids are an important part of plant nutritional quality because they serve as essential human micronutrients needed to support human vision, immune health, and cognitive performance [28][29][30][31]. We recently reported that a combination of elevated CO 2 and continuous exposure to high intensity light strongly depressed carotenoid-to-biomass ratios for β-carotene, lutein, and zeaxanthin [18]. Previous reports on the effect of elevated CO 2 on foliar carotenoid levels have varied by plant species and growth conditions [32].…”