ダイズ小植物体葉身アポプラストへの溶液連続導入法の確立と根粒超多着生形質解明への応用  [in Japanese] Establishment of a Method Enabling Continuous Liquid-Introduction into Apoplast of Soybean-Plantlet Leaf, and Its Application to Elucidating Supernodulating-Trait of NOD1-3  [in Japanese]

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Author(s)

    • 有馬 泰紘 Arima Yasuhiro
    • 国立大学法人東京農工大学大学院共生科学技術研究部生命農学部門 Fac. Agric., Tokyo Univ. Agric. Technol.

Abstract

1)ダイズ根粒超多着生現象に関与する葉身部由来未知物質のin situな効果を,根粒形成数の変化を指標として検定可能にするために,本葉1枚を挿し木して発根させた小植物体を作成し,葉身維管束アポプラストヘ導管負圧を利用して試料溶液を連続導入する方法を考案した,この方法によれば,根粒菌接種後5日間程度の試料溶液導入により,試料溶液のシステミックな根粒形成制御活性を検定することが可能であると判断された.2)NOD1-3・Williams82小植物体の葉身アポプラストヘ尿素溶液を導入し,両小植物体でStage 1, Stage 2いずれの根粒原基数も減少し,特にNOD1-3小植物体での減少が顕著であることから,地上部から根部に輸送される窒素の量と形態によってはNOD1-3の根粒形成が鋭敏に抑制されることが明らかになった.導入された重窒素標識尿素の動態から,導入尿素に由来する窒素が活発に根部に輸送され同化されたことが明らかになり,小植物体葉身維管束のアポプラストに導入された物質のうち師管・伴細胞複合体にloadingされる物質は,根部に活発に輸送されると考えられた.3)NOD1-3・Williams82小植物体の葉身アポプラストヘ明暗反復条件下と連続暗条件下でショ糖溶液を導入し,NOD1-3小槌物体とWilliams82小植物体の根が光合成産物を十分に供給されている場合も,ほとんど供給されていない場合も,またほぼ同程度の糖を供給されている場合も,両小植物体間には根粒原基形成とその発達に明瞭な差があり,NOD1-3の根粒超多着生形質は根部に対する光合成産物の供給水準とは直接関係しないことが明らかになった.

Some putative key-substances translocated from leaves to roots were suggested to be involved in the supernodulation trait of NOD1-3, a mutant of soybean (Glycine max [L.] Merr.) cv. Williams. To search such key-substances, it is necessary to establish a bioassay-system which enables us to introduce substances continuously into leaves and to assess their effects on root nodulation. As a bio-assay system,.plantlets of 7-10 day-old cuttings were prepared using the first trifoliolate of soybean cv. Williams82 and NOD1-3, and applied to assess the effects of continuous introduction of 438 mM sucrose and 167 mM ^<15>N-labeled urea solutions on the formation of root-nodule meristem. The solutions were introduced into apoplast of vascular bundle of the plantlet leaf by self-suction via cut-surface of petiolule of the central foliolate. Root nodule meristems were microscopically inspected at the 5th day after rhizobium inoculation, which had been done after initiation of the continuous introduction. Urea introduction significantly repressed both emergence and development of root nodule meristem, especially in NOD1-3 plantlet. ^<15>N-analyses revealed that a significant amount of nitrogen originating from introduced urea was translocated to roots at the fifth day after initiation of ^<15>N-feeding. Sucrose introduction enhanced both emergence and development of root nodule meristem, irrespective-of the genotype or light condition. Conspicuous difference in root nodule formation between plantlets of NOD1-3 and Williams82 did never disappear under any conditions of exhaustion, normal or plentiful phtosynthate supply to plantlet roots. In our study, the liquids were successfully introduced into plantlets continuously for 5-7 days and some substances introduced into foliolates were expected to be translocatable to root. It was concluded that our bioassay system is applicable to searching for key substances involved in supernodulation phenomenon.

Journal

  • Japanese Journal of Soil Science and Plant Nutrition

    Japanese Journal of Soil Science and Plant Nutrition 75(6), 685-691, 2004

    Japanese Society of Soil Science and Plant Nutrition

References:  25

Cited by:  1

Codes

  • NII Article ID (NAID)
    110001755293
  • NII NACSIS-CAT ID (NCID)
    AN00195767
  • Text Lang
    JPN
  • Article Type
    Journal Article
  • ISSN
    0029-0610
  • NDL Article ID
    7178982
  • NDL Source Classification
    ZR7(科学技術--農林水産--農産)
  • NDL Call No.
    Z18-331
  • Data Source
    CJP  CJPref  NDL  NII-ELS  J-STAGE  JASI 
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