Plant Reproduction

, Volume 27, Issue 2, pp 59–68

Exploring the role of a stigma-expressed plant U-box gene in the pollination responses of transgenic self-incompatible Arabidopsis thaliana

Original Article

DOI: 10.1007/s00497-014-0240-4

Cite this article as:
Zhang, J., Rea, A.C., Fu, T. et al. Plant Reprod (2014) 27: 59. doi:10.1007/s00497-014-0240-4

Abstract

Recognition of “self” pollen in the self-incompatibility (SI) response of the Brassicaceae is determined by allele-specific interaction between the S-locus receptor kinase (SRK), a transmembrane protein of the stigma epidermis, and its ligand, the pollen coat-localized S-locus cysteine-rich (SCR) protein. The current model for SRK-mediated signaling proposes a central role for the plant U-box (PUB) Armadillo repeat-containing protein ARC1, an E3 ligase that interacts with, and is phosphorylated by, the kinase domain of SRK. According to the model, activated ARC1 causes the degradation of factors required for successful pollen tube growth. However, Arabidopsis thaliana plants transformed with functional SRK and SCR genes isolated from self-incompatible A. lyrata can express an intense SI response despite lacking a functional ARC1 gene. Here, we tested the possibility that a different member of the A. thaliana PUB protein family might have assumed the role of ARC1 in SI. Toward this end, we analyzed the AtPUB2 gene, which is annotated as being highly expressed in stigmas. Our functional analysis of a T-DNA insertion pub2 allele, together with yeast two-hybrid interaction assays and reporter analysis of AtPUB2 promoter activity, demonstrates that AtPUB2 does not function in SI. The results leave open the question of whether the proposed model of ARC1-mediated signaling applies to transgenic SRKSCR self-incompatible A. thaliana plants.

Keywords

Self-incompatibility Arabidopsis thaliana S-locus receptor kinase ARC1 

Supplementary material

497_2014_240_MOESM1_ESM.docx (21 kb)
Supplementary material 1 (DOCX 21 kb)

Copyright information

© Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  1. 1.National Key Laboratory of Crop Genetic ImprovementHuazhong Agricultural UniversityWuhanChina
  2. 2.Department of Plant Biology, 412 Mann Library BuildingCornell UniversityIthacaUSA
  3. 3.Department of BiologySage College of AlbanyAlbanyUSA