Genome‐wide analysis of the callose enzyme families of fertile and sterile flower buds of the Chinese cabbage (Brassica rapa L. ssp. pekinensis)

Abstract

Callose is a β‐1,3‐glucan commonly found in higher plants that plays an important role in regulating plant pollen development. It is synthesized by glucan synthase‐like (GSL) and is degraded by the enzyme endo‐1,3‐β‐glucosidase. However, genome‐wide analyses of callose GSL and endo‐1,3‐β‐glucosidase enzymes in fertile and sterile flower buds of Chinese cabbage have not yet been reported. Here, we show that delayed callose degradation at the tetrad stage may be the main cause of microspore abortion in Chinese cabbage with nuclear sterility near‐isogenic line ‘10L03’. Fifteen callose GSLs and 77 endo‐1,3‐β‐glucosidase enzymes were identified in Chinese cabbage. Phylogenetic, gene structural and chromosomal analyses revealed that the expansion occurred due to three polyploidization events of these two gene families. Expression pattern analysis showed that the GSL and endo‐1,3‐β‐glucosidase enzymes are involved in the development of various tissues and that the genes functionally diverged during long‐term evolution. Relative gene expression analysis of Chinese cabbage flowers at different developmental stages showed that high expression of the synthetic enzyme BraA01g041620 and low expression of AtA6‐homologous genes (BraA04g008040, BraA07g009320, BraA01g030220 and BraA03g040850) and two other genes (BraA10g020080 and BraA05g038340) for degrading enzymes in the meiosis and tetrad stages may cause nuclear sterility in the near‐isogenic line ‘10L03’. Overall, our data provide an important foundation for comprehending the potential roles of the callose GSL and endo‐1,3‐β‐glucosidase enzymes in regulating pollen development in Chinese cabbage.

Genome-wide analysis of the CalS gene family in cotton reveals their potential roles in fiber development and responses to stress

“…The protein sequence length of CalSs ranged from 1,494 to 1,979 amino acids, with an average MW of 212.88 kDa, and shared high similarity to the Arabidopsis thaliana CalS proteins ( Hong, Delauney & Verma, 2001 ). The isoelectric point (PI) values of the above genes were all greater than 7, indicating that CalSs in cotton were alkaline, which was the same as the biochemical properties of the CalSs in Chinese cabbage and Brassica ( Pu et al, 2019 ; Liu, Zou & Fernando, 2018 ). The CalSs were most likely localized in the plasma membrane, as predicted in Arabidopsis thaliana and Chinese cabbage ( Pu et al, 2019 ; Zavaliev et al, 2011 ).…”

“…The isoelectric point (PI) values of the above genes were all greater than 7, indicating that CalSs in cotton were alkaline, which was the same as the biochemical properties of the CalSs in Chinese cabbage and Brassica ( Pu et al, 2019 ; Liu, Zou & Fernando, 2018 ). The CalSs were most likely localized in the plasma membrane, as predicted in Arabidopsis thaliana and Chinese cabbage ( Pu et al, 2019 ; Zavaliev et al, 2011 ).…”

“…Due to the importance of callose, the callose synthase gene family has been identified in various plants. To date, it has been reported as 12 AtCalSs in Arabidopsis thaliana ( Hong, Delauney & Verma, 2001 ), 12 CsCalSs in Citrus sinensis ( Granato et al, 2019 ), 32 BnCalSs in Brassica napus ( Liu, Zou & Fernando, 2018 ), eight VvCalSs in Vitis vinifera ( Yu et al, 2016 ), seven HvCalSs in Hordeum vulgare ( Schober et al, 2009 ), 15 BraCalSs in Chinese cabbage ( Pu et al, 2019 ). Generally, according to the evolutionary analysis of CalSs in the above species, the CalS family can be divided into three of four main groups ( Chen & Kim, 2009 ; Liu, Zou & Fernando, 2018 ).…”

Flagellin and mannitol modulate callose biosynthesis and deposition in soybean seedlings

“…GSL proteins have high molecular weight, containing 14–16 transmembrane domains grouped at the N‐terminal and C‐terminal regions, which leaves a central hydrophilic loop facing the cytoplasm (Chen & Kim, 2009; Schneider et al, 2016). The GSL genes have already been investigated in several species, such as grapevine (Yu et al, 2016), Citrus sinensis (Granato et al, 2019), Brassica rapa (Pu et al, 2019), Physcomitrella patens (Schuette et al, 2009), Zea mays (Niu et al, 2021), and Arabidopsis thaliana (Richmond & Somerville, 2000; Verma & Hong, 2001).…”

GhCalS5 is involved in cotton response to aphid attack through mediating callose formation

“…Callose synthase (CalS) is also referred to as glucan synthase-like (GLS; Richmond and Somerville, 2000 ; Verma and Hong, 2001 ). Twelve AtCalSs in Arabidopsis thaliana have been described ( Hong et al, 2001 ), as well as 12 CsCalSs in Citrus sinensis ( Granato et al, 2019 ), 32 BnCalSs in Brassica napus ( Liu et al, 2018 ), 8 VvCalSs in Vitis vinifera ( Yu et al, 2016 ), 7 HvCalSs in Hordeum vulgare ( Schober et al, 2009 ), 15 BraCalSs in Chinese cabbage ( Pu et al, 2019 ), and 27, 28, 16, and 15 GhCalSs, respectively, in Gossypium hirsutum , G. barbadense , G. raimondii , and G. arboreum ( Feng et al, 2021 ) have been reported.…”