Expression of the 2-dehydro-3-deoxyphosphooc-tonate aldolase (KdsA) gene in mulberry leaves (Morus alba L.) is down-regulated under high salt and drought stress.
The oligosaccharide 3-deoxy-d-manno-oct-2-ulosonic acid (Kdo) is a key component of lipopolysaccharide in Gram-negative bacteria, and is also part of the pectic polysaccharide rhamnogalacturonan (RG-II) of the plant cell wall. The enzyme KDO-8-phosphate synthase (KDO8Ps), encoded by the 2-dehydro-3-deoxyphosphooctonate aldolase (KdsA) gene, catalyzes the first step in the synthesis of Kdo. In this study, the complete coding sequence of the KdsA gene from mulberry leaves was cloned and the primary structure of KDO8Ps was deduced. Alignment of the amino acid sequence of KDO8Ps from mulberry with those of five other plant species revealed a high level of evolutionary conservation. A phylogenetic tree analysis demonstrated a short genetic distance among KDO8Ps proteins of different species. Expression of the KdsA gene was higher in the second leaves than in the eighth leaves of mulberry, and was down-regulated under conditions of high salt or drought stress. Our results suggest that KdsA expression is important for the growth of new plant tissues, and is sensitive to harsh environments.
Mulberry Silk Institute of Animal Science and Technology College, Northwest Science and Technology University, Yangling, China.
X B
XB
Yang
Mulberry Silk Institute of Animal Science and Technology College, Northwest Science and Technology University, Yangling, China.
S L
SL
Wu
Mulberry Silk Institute of Animal Science and Technology College, Northwest Science and Technology University, Yangling, China.
D P
DP
Zhu
Mulberry Silk Institute of Animal Science and Technology College, Northwest Science and Technology University, Yangling, China.
H
H
Wu
Mulberry Silk Institute of Animal Science and Technology College, Northwest Science and Technology University, Yangling, China.
T
T
Jiang
Mulberry Silk Institute of Animal Science and Technology College, Northwest Science and Technology University, Yangling, China qyh@nwsuaf.edu.cn.
Y H
YH
Qian
Mulberry Silk Institute of Animal Science and Technology College, Northwest Science and Technology University, Yangling, China.
F
F
Jiao
D000446:Aldehyde-Lyases / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D015536:Down-Regulation; D055864:Droughts; D017343:Genes, Plant; D008969:Molecular Sequence Data; D031625:Morus / Q000235:genetics* / Q000378:metabolism; D010802:Phylogeny; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D054712:Salinity; D055049:Salt Tolerance / Q000235:genetics; D013312:Stress, Physiological
D010940:Plant Proteins; C020011:2-dehydro-3-deoxyphosphooctonate aldolase; D000446:Aldehyde-Lyases