Aquaporins and unloading of phloem-imported water in coats of developing bean seeds

Zhou Y., Setz N., Niemietz C., Qu H., Offler C.E., Tyerman S.D. and Patrick J.W. (2007) Aquaporins and unloading of phloem-imported water in coats of developing bean seeds. Plant, Cell and Environment, 30 12: 1566-1577. doi:10.1111/j.1365-3040.2007.01732.x


Author Zhou Y.
Setz N.
Niemietz C.
Qu H.
Offler C.E.
Tyerman S.D.
Patrick J.W.
Title Aquaporins and unloading of phloem-imported water in coats of developing bean seeds
Journal name Plant, Cell and Environment   Check publisher's open access policy
ISSN 0140-7791
Publication date 2007
Sub-type Article (original research)
DOI 10.1111/j.1365-3040.2007.01732.x
Volume 30
Issue 12
Start page 1566
End page 1577
Total pages 12
Language eng
Subject 1110 Nursing
Abstract Nutrients are imported into developing legume seeds by mass flow through the phloem, and reach developing embryos following secretion from their symplasmically isolated coats. To sustain homeostasis of seed coat water relations, phloem-delivered nutrients and water must exit seed coats at rates commensurate with those of import through the phloem. In this context, coats of developing French bean seeds were screened for expression of aquaporin genes resulting in cloning PvPIP1;1, PvPIP2;2 and PvPIP2;3. These genes were differentially expressed in all vegetative organs, but exhibited their strongest expression in seed coats. In seed coats, expression was localized to cells of the nutrient-unloading pathway. Transport properties of the PvPIPs were characterized by expression in Xenopus oocytes. Only PvPIP2;3 showed significant water channel activity (P os = 150-200 μm s -1) even when the plasma membrane intrinsic proteins (PIPs) were co-expressed in various combinations. Permeability increases to glycerol, methylamine and urea were not detected in oocytes expressing PvPIPs. Transport active aquaporins in native plasma membranes of seed coats were demonstrated by measuring rates of osmotic shrinkage of membrane vesicles in the presence and absence of mercuric chloride and silver nitrate. The functional significance of aquaporins in nutrient and water transport in developing seeds is discussed.
Keyword Functional characterization
Phaseolus vulgaris
Plasma membrane intrinsic proteins
Water transport
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Unknown

Document type: Journal Article
Sub-type: Article (original research)
Collection: Scopus Import
 
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Citation counts: TR Web of Science Citation Count  Cited 30 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 34 times in Scopus Article | Citations
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Created: Tue, 01 Apr 2014, 15:39:31 EST by Yuchan Zhou