Comparison on the carbohydrate metabolic enzyme activities and their gene expression patterns in canola differing seed oil content

Abstract

Carbohydrates are an important regulator of canola seed oil content. However, understanding the physiological regulation by carbohydrates governing seed oil accumulation is fragmented. In the present study, activities of sucrose and starch catalytic enzymes, including neutral and alkaline invertase, sucrose synthase (SUS), and starch phosphorylase, and biosynthetic enzymes, including sucrose phosphate synthase and ADP-glucose pyrophosphorylase, were compared in developing silique and seed of high oil content and low oil content lines (HOCL and LOCL, respectively). The results showed that the HOCL had significantly higher total soluble sugar concentration in the developing silique wall and seed during the seed lipid accumulation stage. Strikingly, all the enzymes showed very strong activities at 20 days after anthesis in the silique wall of the HOCL, which was in agreement with the higher amounts of corresponding gene expression. The result indicated that the homeostasis of the high efficiency of cleavage and biosynthetic of carbohydrates in the HOCL was beneficial for the rapid volume expansion of silique and transportation of carbohydrates, i.e., sucrose and starch, to the seed for utilization. At seed deposition stage, all the enzymes exhibited significantly higher activities in the HOCL than in the LOCL, which was helpful for increased production of carbohydrates. The results of gene expression at seed oil deposition stages revealed that one of the SUS genes, SUS3, showed significantly higher transcript amount in the HOCL than in the LOCL at all stages while most of other genes showed no significant differences between two lines at developing stages. Therefore, SUS3 might be played vital roles in the sucrose cleavage.

Elevated temperature and waterlogging decrease cottonseed quality by altering the accumulation and distribution of carbohydrates, oil and protein

“…The results suggested that NAA synthesis played a predominant role under ET. Similar results were also observed by Zhang et al (2016), who reported that high temperature significantly increased the EAA, NAA and total amino acid (TAA) contents of the grains, whereas the EAA/TAA ratio per kernel declined. However, soil waterlogging reduced the EAA and NAA contents, which was consistent with the changes in plant protein contents in response to waterlogging.…”

“…Carbon metabolism is essential for the regulation of seed growth, while carbohydrates are precursors or intermediates in oil and protein syntheses (Li et al 2016, Yang et al 2017). Sucrose, a metabolite and signalling molecule, is converted to hexose by sucrose synthase and invertase enzymes to provide carbon skeletons for oil and protein syntheses during seed growth (Braun et al 2014).…”

Differential gene expression at different stages of mesocarp development in high- and low-yielding oil palm

“…At maturation, SUS2 was found to be down-regulated in HY compared to LY palms at 20 WAP. This difference has also been observed in a comparison of canola lines with high and low oil content [ 60 ]. The decreased activity of SUS2 may lead to increased lipid accumulation in the mesocarp, suggesting this to be an effect of carbon channeling away from starch towards oil biosynthesis.…”

Review: Omics and Strategic Yield Improvement in Oil Crops

“…For example, proteomics approaches to study near-isogenic sunflower varieties differing in seed oil traits revealed that fructokinase, plastid phosphoglycerate kinase, enolase proteins were up-regulated in the high-oil line while phosphofructokinase, cytosolic phosphoglucomutase, and cytosolic phosphoglycerate kinase were up-regulated in the low-oil variety [40]. Omics analysis of Jatropha curcas [41], soybean [42,43], Brassica napus [44,45], and maize [46] with different lipid content has also been reported. Some studies have used comparative proteomics approaches on lipid regulation between different types of oilseeds [14,47].…”

“…However, upon maturation, chlorophyll content continued to increase, but leaf nitrogen decreased dramatically until leaf 32. No significant changes in either chlorophyll and nitrogen content were observed in leaves [33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49]. Following this study, the distribution of natural 13 C in oil palm leaves was investigated.…”