A novel ATM-dependent X-ray-inducible gene is essential for both plant meiosis and gametogenesis.
DNA damage in Arabidopsis thaliana seedlings results in upregulation of hundreds of genes. One of the earliest and highest levels of induction is displayed by a previously uncharacterized gene that we have termed X-ray induced 1 (XRI1). Analysis of plants carrying a null xri1 allele revealed two distinct requirements for this gene in plant fertility. XRI1 was important for the post-meiotic stages of pollen development, leading to inviability of xri(-) pollen and abnormal segregation of the mutant allele in heterozygous xri1(+/-) plants. In addition, XRI1 was essential for male and female meiosis, as indicated by the complete sterility of homozygous xri1 mutants due to extensive chromosome fragmentation visible in meiocytes. Abolition of programmed DNA double-strand breaks in a spo11-1 mutant background failed to rescue the DNA fragmentation of xri1 mutants, suggesting that XRI1 functions at an earlier stage than SPO11-1 does. Yeast two-hybrid studies identified an interaction between XRI1 and a novel component of the Arabidopsis MND1/AHP2 complex, indicating possible requirements for XRI1 in meiotic DNA repair.
Dean
Philip J
PJ
Centre for Plant Sciences, University of Leeds, Leeds, UK. C.E.West@leeds.ac.uk
Siwiec
Tanja
T
Waterworth
Wanda M
WM
Schlögelhofer
Peter
P
Armstrong
Susan J
SJ
West
Christopher E
CE
D000483:Alleles; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism / Q000528:radiation effects; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism* / Q000528:radiation effects; D003001:Cloning, Molecular; D053903:DNA Breaks, Double-Stranded; D053938:DNA Fragmentation; D004260:DNA Repair; D018744:DNA, Plant / Q000235:genetics; D035264:Flowers / Q000254:growth & development; D005718:Gametogenesis / Q000235:genetics*; D008540:Meiosis / Q000235:genetics* / Q000528:radiation effects; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D014965:X-Rays; D000099257:Meiotic Recombination Protein SPO11
D029681:Arabidopsis Proteins; D018744:DNA, Plant; C477460:Spo11-1 protein, Arabidopsis; D000099257:Meiotic Recombination Protein SPO11