Sergeant Kjell, Printz Bruno, Guerriero Gea, Renaut Jenny, Lutts Stanley, Hausman Jean-Francois
Environmental Research and Innovation (ERIN) Department, Luxembourg Institute of Science and Technology (LIST), 4362 Esch/Alzette, Luxembourg.
Groupe de Recherche en Physiologie végétale (GRPV), Université catholique de Louvain, Earth and Life Institute Agronomy (ELI-A), 1348 Louvain-la-Neuve, Belgium.
Biology (Basel). 2019 Aug 19;8(3):60. doi: 10.3390/biology8030060.
In this study, the cell-wall-enriched subproteomes at three different heights of alfalfa stems were compared. Since these three heights correspond to different states in stem development, a view on the dynamics of the cell wall proteome during cell maturation is obtained. This study of cell wall protein-enriched fractions forms the basis for a description of the development process of the cell wall and the linking cell wall localized proteins with the evolution of cell wall composition and structure. The sequential extraction of cell wall proteins with CaCl, EGTA, and LiCl-complemented buffers was combined with a gel-based proteome approach and multivariate analysis. Although the highest similarities were observed between the apical and intermediate stem regions, the proteome patterns are characteristic for each region. Proteins that bind carbohydrates and have proteolytic activity, as well as enzymes involved in glycan remobilization, accumulate in the basal stem region. Beta-amylase and ferritin likewise accumulate more in the basal stem segment. Therefore, remobilization of nutrients appears to be an important process in the oldest stem segment. The intermediate and apical regions are sites of cell wall polymer remodeling, as suggested by the high abundance of proteins involved in the remodeling of the cell wall, such as xyloglucan endoglucosylase, beta-galactosidase, or the BURP-domain containing polygalacturonase non-catalytic subunit. However, the most striking change between the different stem parts is the strong accumulation of a DUF642-conserved domain containing protein in the apical region of the stem, which suggests a particular role of this protein during the early development of stem tissues.
在本研究中，对苜蓿茎三个不同高度处富含细胞壁的亚蛋白质组进行了比较。由于这三个高度对应于茎发育的不同阶段，因此得以了解细胞壁蛋白质组在细胞成熟过程中的动态变化。对富含细胞壁蛋白质的组分进行的这项研究，为描述细胞壁的发育过程以及将细胞壁定位蛋白与细胞壁组成和结构的演变联系起来奠定了基础。采用氯化钙、乙二醇双乙醚二胺四乙酸（EGTA）和氯化锂补充缓冲液对细胞壁蛋白进行顺序提取，并结合基于凝胶的蛋白质组学方法和多变量分析。尽管在茎尖和中间区域之间观察到最高的相似性，但每个区域的蛋白质组模式都具有特征性。结合碳水化合物并具有蛋白水解活性的蛋白质，以及参与聚糖转运的酶，在茎基部区域积累。β-淀粉酶和铁蛋白同样在茎基部节段积累更多。因此，营养物质的转运似乎是最老茎节段中的一个重要过程。如参与细胞壁重塑的蛋白质（如木葡聚糖内切葡聚糖酶、β-半乳糖苷酶或含BURP结构域的多聚半乳糖醛酸酶非催化亚基）的高丰度所示，中间和顶端区域是细胞壁聚合物重塑的部位。然而，不同茎段之间最显著的变化是在茎尖区域强烈积累了一种含有DUF642保守结构域的蛋白质，这表明该蛋白质在茎组织早期发育过程中具有特殊作用。
