TITLE:
Identification and Expression Analysis of Regulatory Genes Induced by Near-Ultraviolet Irradiation in Bipolaris oryzae
AUTHORS:
Junichi Kihara, Nozomi Tanaka, Makoto Ueno, Sakae Arase
KEYWORDS:
Bipolaris oryzae, Gene Expression, Near-Ultraviolet (NUV), Quantitative Real-Time PCR, Suppression Subtractive Hybridization, UVB
JOURNAL NAME:
Advances in Microbiology,
Vol.4 No.5,
April
15,
2014
ABSTRACT:
Bipolaris oryzae is the causal agent of brown leaf spot
disease in rice, and its asexual spore (conidium) formation is known to be
induced by near-ultraviolet (NUV) irradiation. In order to reveal the
photomorphogenic response and to identify new genes upregulated by NUV
irradiation, suppression subtractive hybridization (SSH) was carried out in B. oryzae. To confirm the differential
gene expression in NUV-irradiated mycelia, quantitative real-time PCR (qRT-PCR)
analysis was performed among 301 genes arbitrarily chosen from 1170 cDNA
clones. The expression of 46 genes (named NUV01 to NUV46) was found to be
significantly enhanced (>4-fold) by NUV irradiation. Sequence analysis
revealed that 23 out of the 46 sequences (50%) showed significant matches to
known fungal genes. The 46 genes were categorized as either BLR1-dependent or
BLR1-independent expression groups using the BLR1-deficient mutant, which presumably lacks the
blue/UVA-absorbing photoreceptor. This finding demonstrates that NUV
irradiation can induce gene regulation, and that this response may be mediated
by both a blue/UVA-absorbing photoreceptor and an as-yet-unidentified photoreceptor
in B. oryzae.