Change in wall composition of transfer and aleurone cells during wheat grain development

Abstract

In addition to the starchy endosperm, a specialized tissue accumulating storage material, the endosperm of wheat grain, comprises the aleurone layer and the transfer cells next to the crease. The transfer cells, located at the ventral region of the grain, are involved in nutrient transfer from the maternal tissues to the developing endosperm. Immunolabeling techniques, Raman spectroscopy, and synchrotron infrared micro-spectroscopy were used to study the chemistry of the transfer cell walls during wheat grain development. The kinetic depositions of the main cell wall polysaccharides of wheat grain endosperm, arabinoxylan, and (1-3)(1-4)-β-glucan in transfer cell walls were different from kinetics previously observed in the aleurone cell walls. While (1-3)(1-4)-β-glucan appeared first in the aleurone cell walls at 90°D, arabinoxylan predominated in the transfer cell walls from 90 to 445°D. Both aleurone and transfer cell walls were enriched in (1-3)(1-4)-β-glucan at the mature stage of wheat grain development. Arabinoxylan was more substituted in the transfer cell walls than in the aleurone walls. However, arabinoxylan was more feruloylated in the aleurone than in the transfer cell walls, whatever the stage of grain development. In the transfer cells, the ferulic acid was less abundant in the outer periclinal walls while para-coumarate was absent. Possible implications of such differences are discussed.

Current potential and limitations of immunolabeling in cereal grain research

“…However, the outer layers (bran without aleurone), transfer cells, and the embryo (germ) remain less well characterized (Beaugrand, et al, 2005;Chen, et al, 2012;Jerkovic, et al, 2010;Robert, et al, 2011). Table 1.…”

“…The location of (13),(14)--D-glucans has also been identified by immunolabeling in other cereals such as barley Wilson, et al, 2006), maize (Carpita & McCann, 2010), oat and rye . In addition to their localization, a better understanding of (13),(14)--D-glucan biosynthesis (Carpita & McCann, 2010;Robert, et al, 2011;Wilson, et al, 2006) and function Robert, et al, 2011) has been achieved by immunolabeling.…”

“…The distribution of (13),(14)--D-glucans in the cell walls of mature wheat grains has been investigated using immunofluorescence Guillon, et al, 2004;Philippe, et al, 2006;Robert, et al, 2011) and immunogold electron microscopy Philippe, et al, 2006), using a specific monoclonal antibody. The location of (13),(14)--D-glucans has also been identified by immunolabeling in other cereals such as barley Wilson, et al, 2006), maize (Carpita & McCann, 2010), oat and rye .…”

“…Maize (Galuszka et al, 2005) Aleurone Arabinoxylan Wheat (Beaugrand et al, 2005;Beaugrand, Reis, et al, 2004;Guillon et al, 2004;Lovegrove et al, 2013;Philippe et al, 2006;Philippe et al, 2007;Robert et al, 2011;Suliman et al, 2013); oat, rye ; barley Xylan Wheat (Lovegrove et al, 2013) Xyloglucan Barley (13),(14)--D-glucan Wheat Philippe et al, 2006;Robert et al, 2011;; barley Callose Wheat (Philippe et al, 2006); barley (Wilson et al, 2012) Mannan Barley Ferulic acid Wheat (Philippe et al, 2007;Robert et al, 2011) p-Coumaric acid Wheat Tranquet et al, 2009) Xylanase Wheat (Beaugrand, Cronier, et al, 2004;Beaugrand et al, 2005;Beaugrand, Reis, et al, 2004) Glycosyltransferase Wheat (Suliman et al, 2013) Oxalate oxidase Wheat ( Wheat (Van Herpen et al, 2008;Wiley et al, 2007) Oleosin / Caleosin Rice (Chen et al, 2012); oat (Heneen et al, 2008) Puroindolines Wheat (Capparelli et al, 2005) Transfer cells Arabinoxylan Wheat Lovegrove et al, 2013;Robert et al, 2011); oat, rye, barley …”

“…These antibodies have been used to localize ferulic acid and p-coumaric acid, to compare the degree of feruloylation of AX in transfer and aleurone cells, and to monitor changes in p-coumaric acid esters in the cell wall of wheat grains during development (Philippe, et al, 2007;Robert, et al, 2011;Tranquet, et al, 2009). …”