“…Starch is the main photosynthetic carbon sink in duckweed. Generally, duckweed contains starch at a low level when maintained under optimal growth conditions, but starch content drastically increases under stress conditions such as nutrient limitation, salinity, high light, phytohormone treatment, or shifting to a heterotrophic growth mode (Cheng and Stomp, 2009;Guo et al, 2020;Sun et al, 2020;Xu et al, 2012;Yin et al, 2015;Zhao et al, 2014;Zhou et al, 2018). The macronutrients nitrogen (N), phosphorus (P), and sulfur (S) are essential for plant growth and development, participating in the formation of cell structures and high energy molecules (nucleic acids, proteins, chlorophyll, ATP, and phospholipids) (Cai et al, 2013;Sun et al, 2013).…”