Root nodulation is controlled by sensing the R/ FR ratio through phytochrome signaling

2011 Fiscal Year Final Research Report

• Project/Area Number: 21657017
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Single-year Grants
• Research Field: Plant molecular biology/Plant physiology
• Research Institution: Saga University
• Principal Investigator: SUZUKI Akihiro 佐賀大学, 農学部, 准教授 (50305108)
• Project Period (FY): 2009 – 2011
• Keywords: 根粒 / 共生 / フィトクロム / 光形態形成 / 植物微生物相互作用 / ジャスモン酸

Research Abstract

Light is critical for supplying carbon to the energetically expensive, nitrogen-fixing symbiosis between legumes and rhizobia. In this study, I show that Phytochrome B(phyB) is part of the monitoring system to detect suboptimal light conditions, which normally suppress Lotus japonicus nodule development following Mesorhizobium loti inoculation. I found that the number of nodules produced by L. japonicus phyB mutants is significantly reduced compared to that of wild-type MG20. To explore causes other than photoassimilate production, the possibility that local control by the root genotype occurred was investigated by grafting experiments. The results showed that the shoot and not the root genotype is responsible for root nodule formation. To explore systemic control mechanisms exclusive of photoassimilation, we moved wild-type MG20 plants from white light to conditions that differed in their ratios of low or high red(R)/ far-red(FR) light. In low R/ FR light, the number of MG20 root nodules dramatically decreased compared to plants grown in high R/ FR even though photoassimilate content was higher for plants grown under low R/ FR. Also, the expression of jasmonic acid(JA)-responsive genes decreased in both low R/ FR light-grown wild-type and in white light-grown phyB mutant plants, and correlated with decreased JA-Ile content in the phyB mutant. Moreover, both infection thread formation and root nodule formation were positively influenced by JA treatment of wild-type plants grown in low

Research Products

• [Journal Article] Lotus japonicus nodulation is photomorphogenetically controlled by sensing the R/ FR ratio through JA signaling (2011)
  • Author(s): Akihiro Suzuki, Lalith Suriyagoda, Tamaki Shigeyama, Akiyoshi Tominaga, Masayo Sasaki, Yoshimi Hiratsuka, Aya Yoshinaga, Susumu Arima, Sakae Agarie, Tatsuya Sakai, Sayaka Inada, Yusuke Jikumaru, Yuji Kamiya, Toshiki Uchiumi, Mikiko Abe, Masatsugu Hashiguc
  • Journal Title: Proceedings of the National Academy of Sciences Volume: vol.108 Pages: 16837-16842
• [Journal Article] Additional cause for reduced JA-Ile in the root of a Lotus japonicus phyB mutant
  • Author(s): Tamaki Shigeyama, Akiyoshi Tominaga, Susumu Arima, Tatsuya Sakai, Sayaka Inada, Yusuke Jikumaru, Yuji Kamiya, Toshiki Uchiumi, Mikiko Abe, Masatsugu Hashiguchi, Ryo Akashi, Ann M. Hirsch and Akihiro Suzuki
  • Journal Title: Plant Signaling and Behavior Volume: (in press)
• [Presentation] Lotus japonicus nodulates when it sees red (2011)
  • Author(s): Akihiro Suzuki, Lalith Suriyagoda, Tamaki Shigeyama, Akiyoshi Tominaga, Masayo Sasaki, Yoshimi Hiratsuka, Aya Yoshinaga, Susumu Arima, Sakae Agarie, Tatsuya Sakai, Sayaka Inada, Yusuke Jikumaru, Yuji Kamiya, Toshiki Uchiumi, Mikiko Abe, Masatsugu Hashiguc
  • Organizer: 第17回世界窒素固定会議
  • Place of Presentation: フリーマントル(オーストラリア)
  • Year and Date: 20111127-1201
• [Presentation] 根粒形成はJAシグナリングを介したR/ FR比受容反応である (2011)
  • Author(s): 重山珠紀, Lalith Suriyagoda, 富永晃好, 佐々木雅代, 平塚芳美, 吉永綾, 有馬進, 東江栄, 酒井達也, 稲田さやか, 軸丸祐介, 神谷勇治, 内海俊樹, 阿部美紀子, 橋口正嗣, 明石良, 佐藤修正, 金子貴一, 田畑哲之, Ann M. Hirsch, 鈴木章弘
  • Organizer: 植物微生物研究会第21回研究交流会
  • Place of Presentation: 岡山市
  • Year and Date: 20110920-0922
• [Book] 根粒菌および菌根菌共生.最近の分子遺伝学の進歩感染・根粒形成と植物ホルモン,「植物の生長調節」 (2011)
  • Author(s): 鈴木章弘, 廣田敦子, 林誠特集
  • Total Pages: 112-119
• [Remarks]
  • URL: http://extwww.cc.saga-u.ac.jp/~azuki/top.html