Ethylene-induced changes in lignification and cell wall-degrading enzymes in the roots of mungbean (Vigna radiata) sprouts.
As an important regulator, ethylene inhibits root growth and development in plants. To determine the mechanism of ethylene on root elongation growth and lateral root formation, ethylene-induced lignification and cell wall-degrading enzymes in the roots of mungbean sprouts were tested. We initially observed that primary root elongation and lateral root numbers were inhibited, while lignin content was enhanced by ethephon (ETH). Cell wall remolding proteins, polygalacturonase (PG) and carboxymethyl cellulose (Cx) activities were reduced, but α-expansins and xyloglucan endotransglucosylases/hydrolases (XTH) were enhanced by ETH. The promotion in lignin production was correlated with changes in activities of key lignin biosynthesis enzymes and hydrogen peroxide (H2O2) content. These actions induced by ETH were altered via treatment with an ethylene perception antagonist (Ag+). We subsequently demonstrated that the role of endogenous ethylene in regulating root elongation growth and lateral root formation were correlated with lignification and cell wall-degrading enzymes, respectively. These results suggested that the ethylene-regulated inhibition of primary root elongation growth was caused by an increase in lignification that reinforced the cell wall and shortened root length, and the suppression of lateral root formation was linked to activities of PG, Cx, α-expansins and XTH.
College of Agriculture and Biotechnology, China Agricultural University, Beijing 100193, PR China.
Wei-Na
WN
Huang
Hong-Kai
HK
Liu
Hua-Hua
HH
Zhang
Zhen
Z
Chen
Yang-Dong
YD
Guo
Yu-Fan
YF
Kang
D002266:Carboxymethylcellulose Sodium / Q000378:metabolism; D002473:Cell Wall / Q000201:enzymology*; D005030:Ethylenes / Q000378:metabolism*; D007887:Fabaceae / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000378:metabolism; D008031:Lignin / Q000096:biosynthesis*; D010937:Plant Growth Regulators / Q000378:metabolism*; D010940:Plant Proteins / Q000378:metabolism*; D018517:Plant Roots / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism*; D011096:Polygalacturonase / Q000378:metabolism
D005030:Ethylenes; D010937:Plant Growth Regulators; D010940:Plant Proteins; C095825:expansin protein, plant; D008031:Lignin; C036216:ethylene; D006861:Hydrogen Peroxide; D011096:Polygalacturonase; D002266:Carboxymethylcellulose Sodium
Cell wall-degrading enzymes; Ethylene; Lateral root formation; Lignification; Mungbean (Vigna radiata) sprout; Primary root elongation