Root-specific expression of genes for novel glycine-rich proteins cloned by use of an antiserum against xylem sap proteins of cucumber.
Candidate cDNAs for xylem sap proteins (XSPs) were isolated by screening of a cucumber cDNA library prepared from poly(A)+ RNA of cucumber roots with an antiserum raised against the XSPs of cucumber. The patterns of expression of corresponding transcripts and the sequences of the cDNAs were examined. Two cDNAs with a glycine-rich domain in each deduced amino acid sequence and whose transcripts were expressed predominantly in roots were selected for further analysis. Both cDNAs encoded proteins with a putative signal sequence, with similar non-glycine-rich domains at the amino terminal of the encoded polypeptides. The corresponding mRNAs accumulated concurrently with the formation of adventitious roots from cuttings of cucumber hypocotyls and the development of vascular tissues, and strong expression of the mRNAs was detected in the root-hair zone of tap roots. These data suggest that the production of the two novel glycine-rich proteins, which are putative XSPs, might be associated with the functions of the vascular tissues in roots.
Institute of Biological Sciences, University of Tsukuba, Ibaraki, Japan.
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Sakuta
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Oda
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Yamakawa
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Satoh
D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D018553:Cucumis sativus / Q000235:genetics*; D018076:DNA, Complementary / Q000235:genetics; D015870:Gene Expression; D005998:Glycine; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000235:genetics* / Q000276:immunology; D018517:Plant Roots / Q000033:anatomy & histology / Q000235:genetics / Q000378:metabolism*; D021382:Protein Sorting Signals / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D018749:RNA, Plant / Q000235:genetics; D017422:Sequence Analysis, DNA; D014018:Tissue Distribution
C117969:CRGRP protein, Cucumis sativus; D018076:DNA, Complementary; D010940:Plant Proteins; D021382:Protein Sorting Signals; D012333:RNA, Messenger; D018749:RNA, Plant; D005998:Glycine