Molecular cloning and ethylene-inducible expression of Chib1 chitinase from soybean (Glycine max (L.) Merr.).
A soybean seed-specific PR-8 chitinase, named Chib2, has a markedly extended C-terminal segment compared to other plant Chib1 homologues of the PR-8 chitinase family known to date. To further characterize the molecular structure and the expression pattern of this chitinase family, we cloned two typical Chib1-similar cDNAs (Chib1-1 and Chib1-2) from soybeans by PCR-cloning techniques. The deduced primary sequence of Chib1-1 chitinase is composed of a signal peptide segment (26 amino acid residues) and a mature 273 amino acid sequence (calculated molecular mass 28,794, calculated pI 3.7). This Chib1-1 enzyme is more than 90% identical to Chib1-2 chitinase but is below 50% identical to Chib2 enzyme. Thus, we confirmed the occurrence of two distinct classes, Chib1 and Chib2 in the plant PR-8 chitinase family. The Chib1 genes, interrupted by one intron, were found to be up-regulated in response to ethylene in stems and leaves, but scarcely expressed in developing soybean seeds. Chib1 chitinases may be responsible for protecting the plant body from various pathogenic attacks.
Watanabe
A
A
Genetic Engineering Laboratory, National Food Research Institute, Ibaraki, Japan.
Nong
V H
VH
Zhang
D
D
Arahira
M
M
Yeboah
N A
NA
Udaka
K
K
Fukazawa
C
C
D000595:Amino Acid Sequence; D001483:Base Sequence; D015152:Blotting, Northern; D015139:Blotting, Southern; D002688:Chitinases / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D003001:Cloning, Molecular; D017931:DNA Primers / Q000737:chemistry; D018744:DNA, Plant / Q000737:chemistry; D005030:Ethylenes / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010802:Phylogeny; D010937:Plant Growth Regulators / Q000378:metabolism; D010940:Plant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D016133:Polymerase Chain Reaction; D018749:RNA, Plant / Q000737:chemistry; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013025:Glycine max / Q000201:enzymology / Q000235:genetics*
D017931:DNA Primers; D018744:DNA, Plant; D005030:Ethylenes; D010937:Plant Growth Regulators; D010940:Plant Proteins; D018749:RNA, Plant; C036216:ethylene; D002688:Chitinases; C094255:PLC-B protein, Phytolacca americana