Photosynthetic acclimation and adaptation of C4 grasses to low light environments

2018 Fiscal Year Final Research Report

• Project/Area Number: 16H04868
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Crop production science
• Research Institution: Kyushu University
• Principal Investigator: UENO OSAMU 九州大学, 農学研究院, 教授 (70414886)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: C4作物 / トウモロコシ / 弱光順応 / 弱光適応 / 葉構造 / 個葉光合成 / 個体群光合成 / 耐陰性C4植物

Outline of Final Research Achievements

The light environment greatly differs between the upper leaf layer and lower leaf layer in crop canopy. To elucidate the light acclimatization mechanism of leaves in C4 maize canopy, we investigated the photosynthetic responses in sun and shade leaves generated by shading experiment of pot-grown plants, the acclimatization of lower leaves in maize canopy to low light, and the photosynthetic capacity in each leaf layer of maize canopy. We revealed that the lower leaves of canopy, which experience a change of light condition from high to low light intensity with canopy growth, show an intriguing re-acclimatization to the light change. We also confirmed that, although a considerable amount of leaves in maize canopy is exposed to low light, these leaves significantly contribute to canopy photosynthesis. In addition, we found that a shade-tolerant C4 grass acquires unique photosynthetic and morphological adaptability of leaves to low light.

Free Research Field

植物生産生理学

Academic Significance and Societal Importance of the Research Achievements

作物の光合成特性を圃場レベルで明らかにすることは農業上重要である。本研究は、圃場で個体群として栽培されるイネ科C4作物のトウモロコシについて、その光合成の実態を葉の置かれている光環境に着目して解明しようとするものである。また、強光を好むとされるC4植物の中にも陰性環境に適応したものがあり、これらの植物の光合成特性を明らかにすることは、C4作物の個体群光合成を改善していく上で重要な糸口となりうる。