Pumpkin phloem lectin genes are specifically expressed in companion cells.

The Plant cell ·Vol. 4 ·No. 12 ·1992-12-00 ·Pages 1539-48

Bostwick DE, Dannenhoffer JM, Skaggs MI, Lister RM, Larkins BA, Thompson GA

Abstract

Pumpkin phloem exudate contains two abundant phloem proteins: PP1 is a 96-kD protein that forms polymeric filaments in vivo, and PP2 is a 48-kD dimeric lectin. Polyclonal antibodies raised against pumpkin phloem exudate were used to isolate several cDNAs corresponding to PP1 and PP2. RNA gel blot analysis indicated that PP1 is encoded by an mRNA of approximately 2500 nucleotides, whereas PP2 subunits are encoded by an mRNA of 1000 nucleotides. Sequence analysis of PP2 cDNAs revealed a 654-bp open reading frame encoding a 218-amino acid polypeptide; this polypeptide had the carbohydrate binding characteristics of a PP2 subunit. The PP2 mRNA was localized within the phloem of pumpkin hypocotyl cross-sections based on in situ hybridization of a digoxigenin-labeled antisense probe. PP2 mRNA was found within the companion cells in both the bicollateral vascular bundles and the extrafascicular phloem network.

MeSH Terms

Amino Acid Sequence Amino Acids/analysis DNA/genetics,isolation & purification Gene Expression In Situ Hybridization Lectins/chemistry,genetics Molecular Sequence Data Plant Lectins Plants/genetics RNA, Messenger/genetics

Chemicals

Amino Acids Lectins Plant Lectins RNA, Messenger DNA

Authors & Affiliations

6 authors, click to expand affiliations / ORCID

Bostwick D E

Department of Plant Sciences, University of Arizona, Tucson 85721.

Dannenhoffer J M

Skaggs M I

Lister R M

Larkins B A

Thompson G A

References (9)

9 references, click to expand

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Article Info

Journal

The Plant cell

Abbr.

Plant Cell

ISSN

1040-4651

DOI

10.1105/tpc.4.12.1539

Published

1992-12-00

Pages

1539-48

Language

English

Region

England

NLM ID

9208688

PMCID

PMC160240

Subset

External Links

PubMed source DOI: 10.1105/tpc.4.12.1539 PMC Full Text View journal details

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Pumpkin phloem lectin genes are specifically expressed in companion cells.

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