Abstract:

A chlorophyll a/b-binding proteins（CAB）gene，designated as MiCAB2（GenBank
accession No. KT944730），was isolated from mango（Mangifera indica L.‘Jinhuang’）by reverse
transcription PCR and RACE technologies. The full-length of cDNA was 990 bp with an open reading
frame of 795 bp and encoded a putative protein of 246 amino acids. The phylogenetic tree analysis showed
that MiCAB2 had the highest similarity with CAB from Canarium album. In addition，the amino acid
sequences encoded by MiCAB2 contained a typical functional domains of the chlorophyll a/b binding protein，three protein kinase C phosphorylation sites and four N-myristoylation sites，indicating that
MiCAB2 might belong to the family of chlorophyll a/b binding protein. Real-time quantitative PCR
revealed that MiCAB2 was expressed in various tissues of M. indica L. differentially，with ranking by
leaves > flowers，embryo and fruit（about 1/50–1/12 of leaves）> roots and stems（very little）. During
the fruit development，MiCAB2 transcript initiated at bud swelling period，sharply increased to maximum
at floral axis separation period，and followed by a overall decline. In normal embryo，a higher MiCAB2
expression appeared in initial period of embryonic development，then decreased，and recovered to a higher
level before a next sharp decline. A continuous decline in MiCAB2 expression was observed in abortive
embryos. In the alternation of day and night，MiCAB2 transcripts in the day was significantly higher than
that in the night，in which minimum at 10：00 pm o’clock，but highest at in 2：00 pm，MiCAB2 gene can
be induced by different agents of flower forcing by which that ethephon exerted the most positive
regulation followed by potassium nitrate. In contrast，paclobutrazol exhibited the multiple play a role of
negative regulation effect.

Key words: Mangifera indica, MiCAB2, clone, express, flowering regulation, abortive embryo