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Transgenic modification of potato pectic polysaccharides also affects type and level of cell wall xyloglucan
Author(s) -
Huang JieHong,
Jiang Rui,
Kortstee Anne,
Dees Dianka CT,
Trindade Luisa M,
Gruppen Harry,
Schols Henk A
Publication year - 2017
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.8172
Subject(s) - xyloglucan , cell wall , polysaccharide , pectin , biochemistry , galactan , chemistry , monosaccharide
BACKGROUND Genes encoding pectic enzymes were introduced into wild‐type potato Karnico. Cell wall materials were extracted from Karnico and transgenic lines expressing β ‐galactosidase ( β ‐Gal‐14) or rhamnogalacturonan lyase ( RGL ‐18). Pectic polysaccharides from the β ‐Gal‐14 transgenic line exhibited rhamnogalacturonan‐I structural elements with shorter galactan side chains, whereas the RGL ‐18 transgenic line had less rhamnogalacturonan‐I structures than Karnico. Xyloglucan in primary cell walls interacts with pectin and other cell wall polysaccharides and controls cell growth. RESULTS Xyloglucan extracts from transgenic lines had different levels of monosaccharides compared to wild‐type. Most XXGG ‐type xyloglucans from Karnico and RGL ‐18 alkali‐extractable extracts predominantly consisted of XXGG and XSGG building blocks. Karnico and RGL ‐18 4 mol L −1 extracts had small proportions of the XXXG ‐type xyloglucan, whereas β ‐Gal‐14 extracts also contained the XXXG ‐type xyloglucan. The peak ratios of XSGG / XXGG were 1.9, 2.4 and 1.1 for 4 mol L −1 extracts of Karnico, RGL ‐18 and β ‐Gal‐14 lines, respectively. CONCLUSION After transgenic modification on pectin, the xyloglucan building blocks may have been changed. The β ‐Gal‐14 lines mostly present XXXG ‐type repeating units instead of the XXGG ‐type in 4 mol L −1 extracts. The ratio of XSGG / XXGG repeating units also changed, indicating that the transgenic modification of pectin altered xyloglucan structure during plant development. © 2016 Society of Chemical Industry