Plant Mol Biol (2015) 87:541–554
Identiﬁcation of tapetum‑speciﬁc genes by comparing global gene
expression of four different male sterile lines in Brassica oleracea
Yuan Ma · Jungen Kang · Jian Wu · Yingguo Zhu ·
Received: 24 April 2014 / Accepted: 19 January 2015 / Published online: 25 February 2015
© The Author(s) 2015. This article is published with open access at Springerlink.com
expressed in at least one of the MS lines and 104 were
non-pollen expressed genes (NPGs). Most of the identiﬁed
NPGs were tapetum-speciﬁc genes considering that anther
walls were normally developed in all four MS lines. Among
the 104 NPGs, 22 genes were previously reported as being
involved in tapetum development. We further separated the
expressed NPGs into different developmental stages based
on the MS defects. The data obtained in this study are not
only informative for research on tapetum development in B.
oleracea, but are also useful for genetic pathway research
in other related species.
Keywords Brassica oleracea · Tapetum · Gene
expression · Male sterility (MS) · Microarray
Anther development comprises both gametophyte and
anther wall development (Engelke et al. 2002; Ge et al.
2010; Ma and Sundaresan 2010). The connection between
these two relatively independent processes occurs in the
tapetum, a layer of the anther wall. As the innermost of
four somatic layers, the tapetum surrounds developing
reproductive cells and plays an important role in the male
fertility of pollen grains. Its secretory tissue provides pro-
teins, lipids, and other nutrients for pollen development and
exine formation (Mariani et al. 1990; Piffanelli et al. 1998).
Anther development is divided into two main phases:
microsporogenesis and microgametogenesis, and these
are further subdivided into 14 anther stages (Chang et al.
2011; Ma 2005; Sanders et al. 1999; Smyth et al. 1990).
In this research, to simplify these complex developmen-
tal processes, we divided these anther stages it into four
major stages according to anther developmental events:
Abstract The tapetum plays an important role in anther
development by providing necessary enzymes and nutrients
for pollen development. However, it is difﬁcult to identify
tapetum-speciﬁc genes on a large-scale because of the difﬁ-
culty of separating tapetum cells from other anther tissues.
Here, we reported the identiﬁcation of tapetum-speciﬁc
genes by comparing the gene expression patterns of four
male sterile (MS) lines of Brassica oleracea. The abortive
phenotypes of the four MS lines revealed different defects
in tapetum and pollen development but normal anther wall
development when observed by transmission electron
microscopy. These tapetum displayed continuous defective
characteristics throughout the anther developmental stages.
The transcriptome from ﬂower buds, covering all anther
developmental stages, was analyzed and bioinformatics
analyses exploring tapetum development-related genes
were performed. We identiﬁed 1,005 genes differentially
Electronic supplementary material The online version of this
article (doi:10.1007/s11103-015-0287-0) contains supplementary
material, which is available to authorized users.
Y. Ma · Y. Zhu (*)
Key Laboratory of the Ministry of Education for Plant
Developmental Biology, College of Life Sciences, Wuhan
University, Wuhan 430072, China
Y. Ma · J. Wu · X. Wang (*)
Institute of Vegetables and Flowers, Chinese Academy
of Agricultural Sciences, Zhongguancun South Street 12,
Beijing 100087, China
Vegetable Research Center, Beijing Academy of Agriculture
and Forestry Sciences, Landianchang South Street 5,
Beijing 100081, China