BoALG10, an α-1,2 glycosyltransferase, plays an essential role in maintaining leaf margin shape in ornamental kale

Abstract

The morphological diversity of leaf margin shapes is an identifying characteristic of many plant species. In our previous work, BoALG10 (α-1,2 glycosyltransferase) was predicted to be a key regulator of leaf margin shape in ornamental kale (Brassica oleracea var. acephala). An alanine and a leucine residues in the conserved domain of the smooth-margined S0835 were substituted by an aspartate and a phenylalanine, respectively, in the corresponding positions of the feathered-margined F0819. However, the expression pattern and function of this gene remain unclear. Here, we examined the expression patterns of BoALG10 using quantitative real-time PCR, and statistically significant differences of expression existed in nine developmental stages between F0819 and S0835. The BoALG10 protein localized to endoplasmic reticulum. The function of BoALG10 was then examined using complementary mutant assays. The overexpression strains phenocopied the smooth leaf margin after introduced the BoALG10S0835 into the feathered-margined inbred line F0819. Simultaneously, irregular dissections appeared in the leaf margins of knockout mutants KO-1 and KO-2 which generated by CRISPR/Cas9 technology from the smooth-margined inbred line S0835. A microscopic observation showed that the leaf margin cells of the smooth-margined plants S0835 and OE-3 were arranged regularly, while the cells of the feathered-margined plants F0819 and KO-1 were of inconsistent size and distributed in an irregular manner, particularly around the indentations of the leaf. This elucidation of BoALG10 function provides a novel insight into the morphological regulation of leaf margin shape.

BrrA02.LMI1 Encodes a Homeobox Protein That Affects Leaf Margin Development in Brassica rapa

“…In Brassica oleracea , BoLMI1a , a homolog of LMI1 , was also predicted as the candidate gene regulating leaf lobe formation. In addition, Feng et al [ 34 , 35 ] demonstrated that BoALG10 , which encodes a glycosyltransferase, plays a vital role in leaf lobe development. In Brassica rapa , the physical interval at the distal end of chromosome A10, which is composed of a rich quantitative trait locus (QTL) of the lobed leaf trait, is a research hotspot.…”