Figures (2)  Tables (1)

    • Figure 1. 

      Diverse types of plant in situ tissue regeneration systems. (a) Shoot apex regeneration after excision. (b) Tissue reunion after incision. (c) Secondary vascular tissue (SVT) regeneration after bark girdling. (d) Root tip regeneration after excision.

    • Figure 2. 

      The regenerative dynamics and regulatory models of three plants in situ tissue regeneration systems. (a) Secondary vascular tissue (SVT) regeneration after bark girdling and (b) the proposed regulatory model in this system. Dotted lines indicate cell division. (c) Root tip regeneration after excision and (d) the regulatory model in this system. (e) Inflorescence stem reunion after incision and (f) the regulatory model in this system.

    • Regeneration systemsRegulatorsDescriptionRoles in plant in situ regenerationReferences
      SVT regeneration after girdlingAuxinPhytohormoneInducing secondary vascular tissue (SVT) regeneration and required for cambium re-establishment[22,26,31,35]
      Cytokinin (CK)PhytohormonePromoting phloem regeneration, inhibiting vascular cambium restoration in in vitro system by blocking auxin maximum[22, 26]
      PtIAA3AUX/IAAAuxin responsive and induced during SVT regeneration[26]
      PtRR7Type-A response regulatorCK responsive and induced during SVT regeneration[26]
      PtANTAP2/ERFInduced during cambium regeneration[22, 26]
      PtAPLG2-likeInduced during phloem regeneration[22, 26]
      PtCALS7Callose synthaseInduced during phloem regeneration[22, 26]
      Root tip regenerationAuxinPhytohormoneAccumulating at the wounding regions first and then moving distally, and required for the reconstruction of root apical meristem (RAM)[17]
      CKPhytohormoneOverlapping with auxin first and then moving proximally, and required for the reconstruction of RAM[17]
      Jasmonic acid (JA)PhytohormoneStimulating stem cell niche regeneration in RAM[16]
      PLTsAP2/ERFPromoting root quiescent center (QC) re-establishment and root tip regeneration, and determining regenerative potential[71, 76]
      YUCsAuxin synthesisRequired for root tip regeneration[72]
      ARF5ARFActivated by auxin to promote the reconstruction of root tip[10, 42]
      ERF115AP2/ERFActivated by JA, auxin and brassinosteroid (BR) to promote root regeneration after excision or cell ablation[16, 73−75]
      ERF114AP2/ERFActing redundantly with ERF115 to promote root tip regeneration[75]
      ERF109AP2/ERFActivated by JA to promote the reconstruction of root tip[16]
      PAT1GRASInteracting with ERF115 to promote root tip regeneration[73]
      WIND1AP2/ERFRegulated by ERF115 and required for root tip regeneration[73]
      PSK5PhytosulfokineRegulated by ERF115 and required for root tip regeneration[74, 75]
      SCRGRASPromoting QC and cortex cell re-establishment after cell ablation[47, 76]
      SHRGRASPromoting QC and cortex cell re-establishment after cell ablation[47, 76]
      FEZNACPromoting lateral root cap (LRC) cell re-establishment after cell ablation[47]
      SMBNACPromoting LRC cell re-establishment after cell ablation[47]
      Tissue reunion after incisionAuxinPhytohormoneAccumulated above the incision and enhancing JA production to promote inflorescence stem reunion but not cucumber or tomato hypocotyl reunion[20, 64]
      JAPhytohormoneProduced below the incision to promote inflorescence stem reunion[20, 64]
      EthylenePhytohormoneInteracting with auxin and promoting inflorescence stem reunion[14, 64]
      Gibberellin (GA)PhytohormoneRequired for cucumber and tomato hypocotyl reunion but not inflorescence stem reunion[19]
      ARF6 ARF8ARFInduced by auxin above the incision to promote pith cell division[80]
      PIN1Auxin transporterRequired for inflorescence stem reunion[20]
      ANAC071NACInduced by auxin and ethylene to promote cambial cell formation and tissue reconnection during inflorescence stem reunion[20, 48]
      ANAC096NACPromoting cambial cell formation and tissue reconnection during inflorescence stem reunion[48]
      RAP2.6LAP2/ERFInduced by JA but inhibited by auxin and promoting cell division and tissue reunion[64]
      XTH19, XTH20Xyloglucan endotransglucosylaseRegulating the proliferation and elongation of pith cell to promote inflorescence stem reunion[80]
      DOFsDOFInduced by auxin and cell wall damage, and required for inflorescence stem reunion[81]

      Table 1. 

      Roles of molecular regulators in plant in situ regeneration systems.