Evaluation of potential function of non-photochemical quenching as a heat source to chloroplast under chilling stress

• Project/Area Number: 18K14450
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 39020:Crop production science-related
• Research Institution: Hokkaido University
• Principal Investigator: Nakashima Taiken 北海道大学, 農学研究院, 助教 (70710945)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Project Status: Completed (Fiscal Year 2020)
• Budget Amount: ¥2,990,000 (Direct Cost: ¥2,300,000、Indirect Cost: ¥690,000); Fiscal Year 2020: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000); Fiscal Year 2019: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000); Fiscal Year 2018: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
• Keywords: トウモロコシ / 低温ストレス / 光合成 / 熱放散 / レーザー誘起蛍光 / 葉緑体 / 光阻害 / C4光合成 / ススキ

Outline of Final Research Achievements

Short growing season is a major limitation on maize production in high latitude cold regions, leading to high density planting which poses an increased risk of root lodging. In this project, therefore, a comparative study on varietal differences in photosynthetic responses to early stage chilling stress was conducted to seek potential use of late-maturing varieties with improved cold tolerance. Among 18 varieties examined, two hybrids differing in early vigor and photosynthetic traits were identified. Further comparison of these hybrids revealed the importance of higher capacity of non-photochemical quenching (NPQ), as well as of other photosynthetic components.As an additional and potential function of NPQ, effects of heat dissipated through NPQ processes on chloroplast temperature were also evaluated by utilizing a microscope spectroscopy which enables simultaneous monitoring of chlorophyll fluorescence quenching and thermoresponsive fluorescence probe.

Academic Significance and Societal Importance of the Research Achievements

飼料用トウモロコシでは，生育期間の短い早生品種よりも晩生品種の方が収量性や耐倒伏性に優れるが，低温によって栽培期間が制限される寒地では早生品種を密植で栽培することが一般的であり，これが倒伏の一因となっている．そのため，春先の低温に強い晩生品種が育成できれば，雪解け後速やかに播種を行い，生育期間を確保することができる．しかし，温暖な気候に適したトウモロコシは，低温下で光合成能力が著しく低下するため生育が滞る．そこで本研究では，低温下でも高い光合成能力を維持するうでで必要な品種特性を明らかにするため，北海道向け品種の光合成特性の比較を通して耐冷性品種を同定し，その品種特性を明らかにした．

Research Products

• [Journal Article] Saccharum × Miscanthus intergeneric hybrids (miscanes) exhibit greater chilling tolerance of C4 photosynthesis and postchilling recovery than sugarcane (Saccharum spp. hybrids). (2019)
  • Author(s): Kar, S., Zhang, N., Nakashima, T., Villanueva-Morales, A., Stewart, J. R., Sack, J. E., Terajima, Y., Yamada. T.
  • Journal Title: Global Change Biology Bioenergy Volume: 11 Issue: 11 Pages: 1318-1333
  • DOI: 10.1111/gcbb.12632
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Field performance of Saccharum × Miscanthus intergeneric hybrids (Miscanes) under cool climatic conditions of northern Japan (2019)
  • Author(s): Kar, S., Weng, T., Nakashima, T., Villanueva-Morales, A., Stewart, J. R., Sack, J. E., Terajima, Y., Yamada. T.
  • Journal Title: BioEnergy Research Volume: - Issue: 1 Pages: 132-146
  • DOI: 10.1007/s12155-019-10066-x
  • Peer Reviewed / Int'l Joint Research
• [Presentation] 早晩性の異なるトウモロコシ品種における初期生育特性に関わる要因の解析 (2021)
  • Author(s): 石山志穂, 山口寛登, 河野龍悟, 松井康眞, 市川伸次, 柏木純一, 山田 敏彦, 中島大賢
  • Organizer: 第251回日本作物学会講演会
• [Presentation] 早晩性の異なるトウモロコシ品種における子実の登熟ならびに枯れ上がり過程とその関連形質の品種間変異 (2021)
  • Author(s): 山口 寛登, 石山 志穂, 松井 康眞, 市川 伸次, 柏木 純一, 山田 敏彦, 中島 大賢
  • Organizer: 第251回日本作物学会講演会
• [Presentation] 北海道における子実用トウモロコシの増収および耐倒伏性強化に向けた晩生品種利用の検討 (2019)
  • Author(s): 山口寛登
  • Organizer: 日本作物学会