xyloglucan-induced increase in lettuce germination and seedling elongation is not related to the degradation of the exogenous xyloglucan

• Published in: Botany Vol. 91; no. 12; pp. 822 - 829
• Main Authors: Pereira-Netto, Adaucto B, Petkowicz, Carmen L.O
• Format: Journal Article
• Language: English
• Published: Ottawa, ON NRC Research Press 01.12.2013; National Research Council of Canada
• Subjects: 2,4-D; Agronomy. Soil science and plant productions; Biological and medical sciences; Botanical research; cell walls; cotyledons; Forestry; Fundamental and applied biological sciences. Psychology; galactose; gel chromatography; Germination; Glucans; glucose; high performance liquid chromatography; Hymenaea courbaril; Lettuce; Liliopsida; Physiological aspects; seedlings; seeds; xyloglucans; xylose; Brazil; Exogenous; Germination; Plant juvenile growth stage; Compositae; Hymenaea courbaril; Cell wall; Degradation; Lettuce; Leguminosae; Vegetable crop; Dicotyledones; Angiospermae; Hardwood forest tree; Spermatophyta; Plant sciences; Expansion; Lactuca sativa; Elongation
• ISSN: 1916-2804; 1916-2790; 1916-2804
• DOI: 10.1139/cjb-2013-0099

Xyloglucans are the main hemicellulosic polysaccharides found in the primary cell walls of dicots and nongraminaceous monocots. Although xyloglucans are building blocks used in plant cell wall assembly, the function of these molecules in the structure and growth of the primary cell wall remains poorly understood. In this study, we demonstrate that treatment of lettuce seeds with a xyloglucan extracted from cotyledons of Hymenaea courbaril L. (Leguminosae (Fabaceae) – Caesalpinioideae) in the 0.1 to 10 nmol·L⁻¹ range resulted in significantly increased germination percentage. In addition, lettuce seedlings grown in the presence of 500 nmol·L⁻¹ xyloglucan presented a significantly larger length compared with seedlings grown in the absence of xyloglucan. Furthermore, the H. courbaril xyloglucan was not able to reverse a 2,4-dichlorophenoxy acetic acid induced inhibition of seedling elongation. High performance size exclusion chromatography (HPSEC) and high-performance liquid chromatography (HPLC) analyses indicated that the xyloglucan-induced enhancement of germination percentage and seedling elongation in lettuce does not rely on the release of monomers, i.e., glucose, xylose, and galactose from the exogenous xyloglucan.