The S receptor kinase determines self-incompatibility in Brassica stigma

The self-incompatibility possessed by Brassica is an intraspecific reproductive barrier by which the stigma rejects self-pollen but accepts non-self-pollen for fertilization. The molecular/biochemical bases of recognition and rejection have been intensively studied. Self-incompatibility in Brassica is sporophytically controlled by the polymorphic S locus. Two tightly linked polymorphic genes at the S locus, S receptor kinase gene (SRK) and S locus glycoprotein gene (SLG), are specifically expressed in the papillar cells of the stigma, and analyses of self-compatible lines of Brassica have suggested that together they control stigma function in self-incompatibility interactions. Here we show, by transforming self-incompatible plants of Brassica rapa with an SRK28 and an SLG 28 transgene separately, that expression of SRK28 alone, but not SLG28 alone, conferred the ability to reject self (S28)-pollen on the transgenic plants. We also show that the ability of SRK28 to reject S28 pollen was enhanced by SLG 28. We conclude that SRK alone determines S haplotype specificity of the stigma, and that SLG acts to promote a full manifestation of the self-incompatibility response.

[1]  J. Stein,et al.  Transgene‐induced silencing of S‐locus genes and related genes in Brassica , 1997 .

[2]  M. Nasrallah,et al.  Pollen[mdash]Stigma Signaling in the Sporophytic Self-Incompatibility Response. , 1993, The Plant cell.

[3]  A. Isogai,et al.  A high degree of homology exists between the protein encoded by SLG and the S receptor domain encoded by SRK in self-incompatible Brassica campestris L. , 1994, Plant & cell physiology.

[4]  C.-H. Chen,et al.  Amino-acid sequence of glycoproteins encoded by three alleles of the S locus of Brassica oleracea , 1987, Nature.

[5]  S. Rothstein,et al.  An S receptor kinase gene in self-compatible Brassica napus has a 1-bp deletion. , 1993, The Plant cell.

[6]  A. Bateman.  Self-incompatibility systems in angiosperms: III. Cruciferae , 1955, Heredity.

[7]  M. Nasrallah,et al.  A genetically defined trans‐acting locus regulates S‐locus function in Brassica , 1992 .

[8]  S. Rothstein,et al.  The Self-Incompatibility Phenotype in Brassica Is Altered by the Transformation of a Mutant S Locus Receptor Kinase , 1998, Plant Cell.

[9]  A. Isogai,et al.  Breakdown of Self-incompatibility in Brassica by the Antisense RNA of the SLG Gene , 1995 .

[10]  Kunihiko,et al.  Factors Influencing Agrobacterium-mediated Transformation of Brassica rapa L. , 1997 .

[11]  S. Rothstein,et al.  The S-locus receptor kinase gene in a self-incompatible Brassica napus line encodes a functional serine/threonine kinase. , 1992, The Plant cell.

[12]  A. Isogai,et al.  Molecular cloning of members of the S-multigene family in self-incompatible Brassica campestris L. , 1995, Plant & cell physiology.

[13]  B. F. Ouellette,et al.  cDNA sequence and homologies of the "57-kDa" nucleotide-binding subunit of the vacuolar ATPase from Arabidopsis. , 1988, The Journal of biological chemistry.

[14]  A. Isogai,et al.  Expression of SLG9 and SRK9 genes in transgenic tobacco , 1996 .

[15]  A. Bateman.  Self-incompatibility systems in angiosperms , 1952, Heredity.

[16]  T. Nishio,et al.  Genomic organization of the S locus: Identification and characterization of genes in SLG/SRK region of S(9) haplotype of Brassica campestris (syn. rapa). , 1999, Genetics.

[17]  J. Stein,et al.  Molecular cloning of a putative receptor protein kinase gene encoded at the self-incompatibility locus of Brassica oleracea. , 1991, Proceedings of the National Academy of Sciences of the United States of America.

[18]  K. Hatakeyama,et al.  Molecular characterization of S locus genes, SLG and SRK, in a pollen-recessive self-incompatibility haplotype of Brassica rapa L. , 1998, Genetics.

[19]  M. Nasrallah,et al.  The male determinant of self-incompatibility in Brassica. , 1999, Science.

[20]  M. Nasrallah,et al.  Genetic evidence for the requirement of the Brassica S-locus receptor kinase gene in the self-incompatibility response , 1994 .

[21]  D. Goring,et al.  A breakdown of Brassica self-incompatibility in ARC1 antisense transgenic plants. , 1999, Science.

[22]  A. Isogai,et al.  A Review of Recent Studies on Homomorphic Self-Incompatibility , 1993 .

[23]  A. Isogai,et al.  Ultrastructure of Papillar Cells in Brassica campestris Revealed by Liquid Helium Rapid-Freezing and Substitution-Fixation Method , 1990 .

[24]  T. Nishio,et al.  Polymorphism of the kinase domain of the S-locus receptor kinase gene (SRK) in Brassica oleracea L. , 1997, Theoretical and Applied Genetics.

[25]  K. Hatakeyama,et al.  Dominance relationships between S-alleles in self-incompatible Brassica campestris L. , 1998, Heredity.

[26]  A. Isogai,et al.  Sequences of S-glycoproteins, products of the Brassica campestris self-incompatibility locus , 1987, Nature.