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Characterization of three members of the multigene family coding for isoforms of the chlorophyll‐ a/b ‐binding protein Lhcb1 in spinach
Author(s) -
Rea Giuseppina,
Volpicella Mariateresa,
De Leo Francesca,
Zolla Lello,
Gallerani Raffaele,
Ceci Luigi R
Publication year - 2007
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.2007.00891.x
Subject(s) - spinach , biology , gene isoform , gene , coding region , untranslated region , genetics , complementary dna , gene family , biochemistry , gene expression , microbiology and biotechnology , messenger rna
Multiple isoforms of the light harvesting complex II (LHCII) chlorophyll a/b binding proteins Lhcb1 and Lhcb2 have been identified in plants, whose precise functions is yet to be understood. In spinach, a proteomic analysis of major antenna proteins showed three homologous short polypeptides, corresponding to putative distinct Lhcb1 isoforms with different phosphorylation sites. In this paper, we report the identification of the complete coding sequences for the three spinach Lhcb1 isoforms. 3′ rapid amplification of cDNA ends (RACE) analysis identifies several transcripts for each single coding region, allowing us to hypothesize the presence in the spinach genome of multiple gene copies, with different 3′‐untranslated region. In leaves, under normal light conditions, about the same relative amounts of the three transcripts are present. However, real‐time polymerase chain reaction analysis shows that under long‐term white light exposure, a differential transcript accumulation occurs. The occurrence of three genes encoding Lhcb1 isoforms supports the hypothesis of a complex organization of spinach LHCII, and a possible specific role for the different isoforms in plant adaptation to different light conditions. Furthermore, the identification of multiple transcripts suggests that the expression of the three coding sequences may be modulated by different regulatory elements.