4.4 RNA-Seq data in response to T. laevis and T.
controversa
Pathogenesis-related (PR) genes and WRKY transcription factors play
important role in defense mechanism and in regulation of defense genes
(Anguelova‐Merhar et al., 2001; Sels et al., 2008; Pandey & Somssich,
2009; Rushton et al., 2010; Bai et al., 2018). We compared the
transcription level between both pathogens infected and control plants
at different wheat anther stages. Our results showed that
transcriptional levels of 81 PR genes after T. laevis and 52 PR
genes after T. controversa were changed. UDT1 is a transcription
factor that plays a key role in the development of the tapetum and is
required for anther male fertility and pollen differentiation (v et al.,
2005; Liu et al., 2010). Additionally, the transcription factor TDR is
involved in the regulation of programmed cell death (PCD) of tapetum and
degradation of male reproductive development (Li et al., 2006). TDR
plays an upstream role in the regulation of tapetum PCD and interacts
with EAT1/DTD (Niu et al., 2013) and may also play a regulatory role in
lipid metabolism involved in pollen wall formation (Zhang et al., 2008).
In this study, the transcription factors UDT1, TDR and EAT1 were
expressed at all stages of anthers development and TDR mostly
down-regulated at fifth stage (1100-1300 µm) support hypothesis that
tapetum cells degraded in the last stages. Polygalacturonase is a cell
wall hydrolytic enzyme, which is related to various cell separation
processes during plant development including; seed germination, anther
dehiscence, organ shedding and fruit ripening (Kim & Patterson, 2006;
Ogawa et al., 2009). In our study, the expression of polygalacturonase
gene was down regulated at all stages of anther development (700-1100
µm), indicating that both pathogens alters the normal structure of
anther development as a result anthers lose their pollination
activities.
According to GO enrichment analysis of differentially expressed genes in
control and both pathogens infected libraries, the results showed that
binding, catalytic activity, membrane part, cell part, metabolic process
and cellular process were had the highest number of DEGs during plant
pathogen interaction (Figure S4 ). GO enrichment analysis
suggest that both pathogens alters the morpho-physiological and defense
mechanisms of the plants (Berger et al., 2007). KEGG is database
resource for understanding high level functions and utilities of a
biological system. This is especially useful for large scale molecular
datasets generated by genome sequencing and other high-throughput
experiment technologies, providing valuable classification for studies
of biological complex process (Kanehisa & Goto, 2000). KEGG enrichment
analysis showed that metabolic and cellular pathways were expressed
significantly at all above anther stages after T. laevis andT. controversa infection. The photosynthesis is a basic
physiological processes of plant growth (Deng et al., 2009). The results
obtained from KEGG analysis of DEGs showed that genes involved
photosynthesis significantly changed after T. laevis and T.
controversa infection (Figure S5 ). Phenylalanine metabolism
are the substrate molecules of primary and secondary metabolic pathways
and have role in the viability of all cells (Adams et al., 2019).
Endoplasmic reticulum are important organelle and have a key role for
protein production destined for the plasma membrane, vacuoles and
apoplast in plants (Eichmann & Schäfer, 2012). Plants hormones are the
key regulators for many functions including primary (plant growth and
development) and secondary (induction of defence programme) (Bolwell,
1997; Yvon & Joanne, 2011). Starch and sucrose have a central role in
the carbon budget of the majority of plants, and plays a dual role in
carbon allocation (MacNeill et al., 2017). Glycolysis have a major role
in respiration rate of the plants by producing the substrates that are
essential for respiration (Megguer et al., 2017). Our results showed
that KEGG analysis of DEGs showed that the genes involved in
phenylalanine metabolism, endoplasmic reticulum, plant hormone signal
transduction, starch, sucrose and glycolysis were significantly changed
after T. laevis and T. controversa infection in different
stages of anther development (Figure S5 ).