A technique for producing high sugar content in tomatoes by disrupting the hormonal balance between scion and rootstock

Research Project

Project/Area Number	17K08016
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Multi-year Fund
Section	一般
Research Field	Agricultural environmental engineering/Agricultural information engineering
Research Institution	Iwate University
Principal Investigator	Matsushima Uzuki 岩手大学, 農学部, 准教授 (70315464)
Project Period (FY)	2017-04-01 – 2022-03-31
Project Status	Completed (Fiscal Year 2021)
Budget Amount *help	¥4,810,000 (Direct Cost: ¥3,700,000、Indirect Cost: ¥1,110,000) Fiscal Year 2019: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000) Fiscal Year 2018: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000) Fiscal Year 2017: ¥2,470,000 (Direct Cost: ¥1,900,000、Indirect Cost: ¥570,000)
Keywords	トマト果実の高糖度化 / 接ぎ木不親和 / オーキシン / 異種間接ぎ木 / 水ストレス / 木部通導組織 / 植物ホルモン / オーキシントランスポーター / 根の肥大 / 根の萎縮 / ナス科 / 通水コンダクタンス / 近赤外線イメージング
Outline of Final Research Achievements	When we investigated root volume changes in scion plants treated with exogenous auxin, there were no significant differences between the auxin-treated and control areas. Conversely, when an auxin transport inhibitor was administered and compared with the control, there was no significant difference between the treated and non-treated areas in the eggplant stand and tomato scion areas, assuming that excess auxin was the cause of the reduction in root mass of the rootstock. In other words, the reduction in root mass of eggplant peduncle tomato scions due to auxin excess was not caused by auxin excess. On the other hand, all tomato scion seedlings showed the morphological changes seen in the inhibition of auxin transporters. The difference in auxin transporter inhibition between eggplant and tomato scions suggests that the auxin transport systems of eggplant and tomato are different.
Academic Significance and Societal Importance of the Research Achievements	ユニークな糖度トマトの生産方法としてトマト穂木をナス台木に接ぐことで高糖度トマトを生産する方法が試みられている．本研究では，ナス穂木とトマト穂木に対するオーキシン輸送体の阻害に差が生じたことから，ナスとトマトのオーキシン輸送のシステムは異なることを明らかにした．すなわち，穂木によって台木に対するホルモン輸送システムが異なって根量が変化し，それによる地上部の水ストレスが高糖度トマトを生産させる．従って，将来的に，まずオーキシン輸送システムを調査し，仕組みが異なる台木と穂木を選択することによって，さらなるトマト果実の高糖度化を目指すことが可能となる．