Changes in cell wall polysaccharides during wheat grain development

Sumitra V. Chanda

Abstract

Changes in low and high molecular weight xyloglucan and pectic polysaccharide content were estimated during grain development in wheat (Triticum aestivum) cultivar Lok-1. Three grains differing in their final dry weight and position on the spike were selected for the investigation. The low molecular weight xyloglucan and high molecular weight xyloglucan were isolated by extracting in 4% KOH and 24% KOH, respectively. Changes in the xyloglucan content (low and high) showed an inverse correlation with water content. However, low molecular weight xyloglucan was more than high molecular weight xyloglucan at all stages of grain growth. Pectic polysaccharides also showed an inverse correlation, with highest content being in the smallest grain and vice versa. Increase in xyloglucan and pectic polysaccharide content coincided with termination of elongation growth thus suggesting its probable role in wall rigidity. It is suggested that cell wall is a dynamic compartment where reorganization occurs by turnover and alteration of wall polysaccharides.