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植物の自然免疫、Pathogen Resistanceの分子遺伝学的研究の第一線で活躍されてい

演者:吉岡 啓子 博士 (Department of Cell and Systems Biology&s_comma; University of

日時: 2006年12月19日(火) 17:00-18:00
場所: 東京理科大学 野田キャンパス 講義棟 4階K409教室 (東武野田線運河駅下車
(JR常磐線 柏駅から運河駅まで12分)

演題: The chimeric Arabidopsis CYCLIC NUCLEOTIDE-GATED ION CHANNEL11/12
activates environmentally sensitive&s_comma; multiple pathogen resistance responses

要旨: To investigate the resistance signaling pathways activated by
pathogen infection&s_comma; we previously identified the Arabidopsis thaliana mutant
constitutive expresser of PR genes22 (cpr22)&s_comma; which displays constitutive
activation of multiple defense responses (Yoshioka et al.&s_comma; 2001). This
activation of pathogen resistance responses is dependent of salicylic acid
accumulation and interestingly&s_comma; environmentally sensitive. High humidity and
high temperature can suppress this activation of pathogen resistance. This
type of sensitivity was also reported for R gene-mediated resistance (Zhou
et al.&s_comma; 2004)&s_comma; thus it is suggested that there is a general factor which is
environmentally sensitive in pathogen resistance signaling. Recently&s_comma; we
identified the cpr22 mutation as a 3-kb deletion that fuses two cyclic
nucleotide-gated ion channel (ATCNGC)-encoding genes&s_comma; ATCNGC11 and ATCNGC12&s_comma;
to generate a novel chimeric gene&s_comma; ATCNGC11/12 (Yoshioka et al.&s_comma; 2006).
Genetic&s_comma; molecular&s_comma; and complementation analyses suggest that ATCNGC11/12&s_comma;
as well as ATCNGC11 and ATCNGC12&s_comma; form functional cAMP-activated CNGCs and
that the phenotype conferred by cpr22 is attributable to the expression of
ATCNGC11/12. However&s_comma; because over-expression of ATCNGC12&s_comma; but not ATCNGC11&s_comma;
suppressed the phenotype conferred by cpr22&s_comma; the development of this
phenotype appears to be regulated by the ratio between ATCNGC11/12 and
ATCNGC12. Analysis of T-DNA-insertion lines suggests that both ATCNGC11 and
ATCNGC12 are positive mediators of pathogen resistance. Currently&s_comma; we are
conducting a comprehensive analysis of the molecular mechanism of
Arabidopsis CNGCs as well as a suppressor screening to identify novel
components in the cpr22-mediated pathogen resistance signaling.

*Yoshioka&s_comma; K.&s_comma; Tsui&s_comma; F.&s_comma; Kachroo&s_comma; P.&s_comma; Sharma&s_comma; S. B.&s_comma; Shah&s_comma; J. and Klessig&s_comma;
D.F. (2001). Environmentally-sensitive&s_comma; SA-dependent defense responses in
the cpr22 mutant of Arabidopsis. Plant J. 26: 447-459.
*Zhou&s_comma; F.&s_comma; Menke&s_comma; F.H.L.&s_comma; Yoshioka&s_comma; K.&s_comma; Moeder&s_comma; W. and Klessig&s_comma; D.F. (2004)
High humidity suppresses ssi4-mediated cell death and disease resistance
upstream of MAP kinase activation&s_comma; H2O2 production and defense gene
expression. Plant J. 39:920-932.
*Yoshioka&s_comma; K.&s_comma; Moeder&s_comma;W.&s_comma; Kang&s_comma;H-G.&s_comma; Kachroo&s_comma;P.&s_comma; Masmoudi&s_comma;K.&s_comma; Berkowitz&s_comma;G.
and Klessig&s_comma; D.F.(2006) The Chimeric Cyclic Nucleotide-Gated Ion Channel
ATCNGC11/12 Activates Multiple Pathogen Resistance Responses. Plant Cell.


朽津 和幸 (Dr. Kazuyuki KUCHITSU)
東京理科大学 大学院 理工学研究科 応用生物科学専攻
 ゲノム創薬研究センター 細胞シグナル制御部門 併任
〒278-8510 千葉県野田市山崎2641
TEL 04-7122-9404
FAX 04-7123-9767
E-mail: kuchitsu@rs.noda.tus.ac.jp