The role of a pollen-expressed Cullin1 protein in gametophytic self-incompatibility in Solanum.
We previously isolated a pollen factor, ui6.1, which encodes a Cullin1 protein (CUL1) that functions in unilateral interspecific incompatibility (UI) in Solanum. Here we show that CUL1 is also required for pollen function in self-incompatibility (SI). We used RNA interference (RNAi) to reduce CUL1 expression in pollen of Solanum arcanum, a wild SI tomato relative. Hemizygous T0 plants showed little or no transmission of the transfer DNA (T-DNA) through pollen when crossed onto nontransgenic SI plants, indicating that CUL1-deficient pollen are selectively eliminated. When crossed onto a related self-compatible (SC) accession lacking active S-RNase, pollen transmission of the T-DNA followed Mendelian ratios. These results provide further evidence for functional overlap between SI and UI on the pollen side and suggest that CUL1 mutations will reinforce SI-to-SC transitions in natural populations only if preceded by loss of pistil S-RNase expression.
C. M. Rick Tomato Genetics Resource Center, Department of Plant Sciences, University of California, Davis, California 95616.
Wentao
W
Li
Roger T
RT
Chetelat
D044842:Cullin Proteins / Q000235:genetics* / Q000378:metabolism; D035264:Flowers / Q000235:genetics / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D010641:Phenotype; D011058:Pollen / Q000235:genetics* / Q000378:metabolism; D034622:RNA Interference; D032322:Solanum / Q000235:genetics* / Q000378:metabolism; D014170:Transformation, Genetic; D019076:Transgenes
C100318:Cullin 1; D044842:Cullin Proteins
Cullin1; Solanum arcanum; gametophytic self-incompatibility; tomato; unilateral incompatibility