Abstract
Sugars play a variety of roles in plants, and their accumulation in seeds and/or surrounding pericarp tissues is distinctly different between grasses and eudicots. However, little is known about the evolutionary pattern of genes involved in sugar accumulation in these two major groups of flowering plants. Here, we compared evolutionary rates, gene duplication, and selective patterns of genes involved in sugar metabolism and transport between grasses and eudicots using six grass species and seven eudicot species as materials. Overall, sugar transporter genes exhibit divergent evolutionary patterns, whereas, sugar metabolism genes showing similar evolutionary pattern between monocots and eudicots. Sugar transporter genes have higher frequencies of recent duplication in eudicots than in grasses and their patterns of evolutionary rate are different. Evidence for divergent selection of these two groups of flowering plants is also observed in sugar transporter genes, wherein, these genes have undergone positive selection in eudicots, but not in grasses. Taken together, these findings suggest that sugar transporter genes rather than sugar metabolism genes play important roles in sugar accumulation in plants, and that divergent evolutionary patterns of sugar transporter genes are associated with the difference of sugar accumulation in storage tissues of grasses and eudicots.
Highlights
Monocots and eudicots are the two major classes of angiosperms
We compared the evolutionary rates, gene duplication, and selective patterns of genes involved in sugar accumulation between grasses and eudicot plants, including four above-mentioned key gene families involved in sugar metabolism, HK, neutral invertase (NI), suc-phosphate synthase (SPS), and sucrose synthase (SUSY), and two sugar transporter gene families, sucrose transporter (SUT) and monosaccharide transporter (MST)
The SUT gene family was composed of three eudicot subfamilies and five grass subfamilies (Fig. 3), and all these eight subfamilies were clustered into three clades (SUT1, SUT2, and SUT4)
Summary
Monocots and eudicots are the two major classes of angiosperms. Eudicots includes many economic crops such as soybean (Glycine max), castor-oil plant (Ricinus communis), tomato (Solanum lycopersicum), and fruit trees such as apple (Malus × domestica) and orange (Citrus sinensis). We compared the evolutionary rates, gene duplication, and selective patterns of genes involved in sugar accumulation between grasses and eudicot plants, including four above-mentioned key gene families involved in sugar metabolism, HK, NI, SPS, and SUSY, and two sugar transporter gene families, SUT and MST. Since phloem transport is not a limited step for sugar accumulation in storage organs such as seeds or fruits[26], the SWEET family was not included in this study. Our study provides insights into the observed divergent evolutionary patterns of genes involved in sugar accumulation in plants, but will contribute to understanding of the observed morphological and physiological differences between grass and eudicot plants
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
