Elucidation of mechanism of ''re-greening'' phenomenon in citrus fruit

2023 Fiscal Year Final Research Report

• Project/Area Number: 20H02976
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 39030:Horticultural science-related
• Research Institution: Shizuoka University
• Principal Investigator: Kato Masaya 静岡大学, 農学部, 教授 (10432197)
• Co-Investigator(Kenkyū-buntansha): 張 嵐翠 静岡大学, 農学部, 特任助教 (20767371) ; 馬 剛 静岡大学, 農学部, 助教 (20767412) ; 本橋 令子 静岡大学, 農学部, 教授 (90332296)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: カンキツ / 回青 / カロテノイド / クロロフィル / フラベド

Outline of Final Research Achievements

In this study, to elucidate the regulatory mechanism of regreening phenomenon in citrus fruit, light irradiation and plant hormones were treated on the fruits on the tree and the cultured flavedos. The results showed that blue light irradiation and Gibberellic acid (GA) treatments promoted the chlorophyll accumulation by increasing the expression level of chlorophyll biosynthetic genes and decreasing the expression level of chlorophyll degradation genes. Whereas, red light, abscisic acid (ABA) and low nitrogen treatments inhibited the chlorophyll accumulation by decreasing the expression levels of chlorophyll biosynthetic genes and increasing the expression levels of chlorophyll degradation genes. These results indicate that the regreening of citrus fruit is positively regulated by blue light and GA, while negatively regulated by red light, ABA and low nitrogen.

Free Research Field

園芸科学

Academic Significance and Societal Importance of the Research Achievements

本研究で明らかにしたカンキツ果実特有の「回青」現象の発生メカニズムはカンキツ果実の成熟過程における着色機構の全容の解明に寄与し、果実着色に関わる光照射、植物ホルモンおよび栄養元素の役割の解明に貢献する。また、回青の発生の鍵転写因子候補の特定はDNAマーカーを利用した回青が発生しにくい新品種の育成に繋がる。さらに、果実の着色技術を開発することで、カンキツ果実の市場価値の向上やロスの減少に直結する。