Effects of Elevated CO2 on Photosynthetic Accumulation, Sucrose Metabolism-Related Enzymes, and Genes Identification in Goji Berry (Lycium barbarum L.).

Yaping Ma,Lihua Song,Yun Xie,Bing Cao,Rong Ha

doi:10.3389/fpls.2021.643555

Yaping Ma, Lihua Song + Show 3 more

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https://doi.org/10.3389/fpls.2021.643555

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Abstract

Goji berry (Lycium barbarum L.) exposure to elevated CO2 (eCO2) for long periods reduces their sugar and secondary metabolite contents. However, sugar accumulation in fruit depends on photosynthesis and photoassimilate partitioning. This study aimed to explore photosynthesis, sugar content, and sucrose metabolism-related enzyme activities in goji berry leaves and fruits under ambient and eCO2 levels, and identify the genes encoding L. barbarum acid invertase (LBAI), L. barbarum sucrose synthase (LBSS), L. barbarum sucrose phosphate synthase (LBSPS), and L. barbarum neutral invertase (LBNI), based on transcriptome profiling. Further, the characterization of four identified genes was analyzed including subcellular localization and expression patterns. In plants grown under eCO2 for 90 or 120 days, the expression of the above-mentioned genes changed significantly as the photosynthetic rate increased. In addition, leaf and fruit sugar contents decreased, and the activities of four sucrose metabolism-related enzymes increased in leaves, while acid and neutral invertase increased in fruits. Protein sequence analysis demonstrated that LBAI and LBNI contain a conservative structure domain belonging to the glycosyl hydrolases (Glyco_hydro) family, and both LBSS and LBSPS belonging to the sucrose synthase (Sucrose_synth) and glycosyltransferase (Glycos_transf) family. Subcellular localization analysis showed that LBAI, LBNI, and LBSS were all located in the nucleus, plasma membrane, and cytoplasm, while LBSPS was located in the plasma membrane. The expressions of LBAI, LBSPS, and LBNI were high in the stems, whereas LBSS was predominantly expressed in the fruits. Our findings provide fundamental data on photosynthesis and sugar accumulation trends in goji berries under eCO2 exposure.

Highlights

Goji berry (Lycium barbarum L.) is a deciduous perennial shrub of the Solanaceae family, traditionally used as a medicinal plant in East Asia (Amagase and Farnsworth, 2011; Pedro et al, 2018)
This study confirmed that chlorophyll, photosynthesis, various sugars, and related enzyme activities in goji berry leaves and fruits were significantly affected by elevated CO2 (eCO2) after 90 and 120 days
L. barbarum acid invertase (LBAI), L. barbarum sucrose synthase (LBSS), L. barbarum sucrose phosphate synthase (LBSPS), and L. barbarum neutral invertase (LBNI) were identified based on transcriptome profiling and the analysis of characteristic, subcellar locations, and expression patterns

Summary

Introduction

Goji berry (Lycium barbarum L.) is a deciduous perennial shrub of the Solanaceae family, traditionally used as a medicinal plant in East Asia (Amagase and Farnsworth, 2011; Pedro et al, 2018). The species has been planted in China for over 2,000 years and contains various bioactive and pharmacological components that promote metabolism and help control diabetes, Goji Berry Response to eCO2 regulate immunity, and protect the nervous system. It is widely used for its unique efficacy in immune regulation and anti-aging and anti-tumor effects. Studies have demonstrated that the whole goji berry plant (fruits, roots, leaves, bark, and flowers) contains a variety of phytochemical components, such as polysaccharides (LBP), flavonoids, carotenoids, alkaloids, amides, peptides, anthraquinones, sterols, natural acids, and glycolipids that have high medicinal values and plays a role in functional food development (Wang et al, 2015; Byambasuren et al, 2019). As a medicinal and food plant, goji berry has attracted increased global attention and, as such, has broad development prospects in the fields of medicine and nutritional health

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