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Effect of sporophytic PIRL9 genotype on post-meiotic expression of the Arabidopsis pirl1;pirl9 mutant pollen phenotype

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Plant intracellular ras-group-related leucine-rich repeat proteins (PIRLs) are a novel class of plant leucine-rich repeat (LRR) proteins structurally related to animal ras-group LRRs involved in cell signaling and gene regulation. Gene knockout analysis has shown that two members of the Arabidopsis thaliana PIRL gene family, PIRL1 and PIRL9, are redundant and essential for pollen development and viability: pirl1;pirl9 microspores produced by pirl1/PIRL1;pirl9 plants consistently abort just before pollen mitosis I. qrt1 tetrad analysis demonstrated that the genes become essential after meiosis, during anther stage 10. In this study, we characterized the phenotype of pirl1;pirl9 pollen produced by plants heterozygous for pirl9 (pirl1;pirl9/PIRL9). Alexander’s staining, scanning electron microscopy, and fluorescence microscopy indicated that pirl1;pirl9 double mutants produced by pirl9 heterozygotes have a less severe phenotype and more variable morphology than pirl1;pirl9 pollen from pirl1/PIRL1;pirl9 plants. Mutant pollen underwent developmental arrest with variable timing, often progressing beyond pollen mitosis I and arresting at the binucleate stage. Thus, although the pirl1 and pirl9 mutations act post-meiosis, the timing and expressivity of the pirl1;pirl9 pollen phenotype depends on the pirl9 genotype of the parent plant. These results suggest a continued requirement for PIRL1 and PIRL9 beyond the initiation of pollen mitosis. Furthermore, they reveal a modest but novel sporophytic effect in which parent plant genotype influences a mutant phenotype expressed in the haploid generation.

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Leucine-rich repeat


Plant intracellular ras-group-related LRR protein


Scanning electron microscopy


  1. Alexander MP (1969) Differential staining of aborted and non-aborted pollen. Stain Technol 41:117–122

  2. Arabidopsis Genome Initiative (2000) Analysis of the genome sequence of the flowering plant Arabidopsis thaliana. Nature 408:796–815

  3. Baez JM, Riveros M, Lehnback C (2002) Viability and longevity of pollen of Nothofagus species in south Chile. N Z J Bot 40:671–678

  4. Belkhadir Y, Subramaniam R, Dangl JL (2004) Plant disease resistance protein signaling: NBS-LRR proteins and their partners. Curr Opin Plant Biol 7:391–399

  5. Bouche N, Bouchez D (2001) Arabidopsis gene knockout: phenotypes wanted. Curr Opin Plant Biol 4:111–117

  6. Briggs GC, Osmont KS, Shindo C, Sibout R, Hardtke CS (2006) Unequal genetic redundancies in Arabidopsis—a neglected phenomenon? Trends Plant Sci 11:492–498

  7. Buchanan SG, Gay NJ (1996) Structural and functional diversity in the leucine-rich repeat family of proteins. Prog Biophys Mol Biol 65:1–44

  8. Claudianos C, Campbell HD (1995) The novel flightless-I gene brings together two gene families, actin-binding proteins related to gelsolin and leucine-rich-repeat proteins involved in Ras signal transduction. Mol Biol Evol 12:405–414

  9. Cushing DA, Forsthoefel NR, Gestaut DR, Vernon DM (2005) Arabidopsis emb175 and other ppr knockout mutants reveal essential roles for pentatricopeptide repeat (PPR) proteins in plant embryogenesis. Planta 221:424–436

  10. Cutler ML, Bassin RH, Zanoni L, Talbot N (1992) Isolation of rsp-1, a novel cDNA capable of suppressing v-Ras transformation. Mol Cell Biol 12:3750–3756

  11. Dafini A, Devan P, Husband B (2005) Practical pollination biology. Enviroquest Ltd, Canada, p 590

  12. Dai P, Xiong WC, Mei L (2006) Erbin inhibits RAF activation by disrupting the sur-8-Ras-Raf complex. J Biol Chem 281:927–933

  13. De Smet I, Voss U, Jurgens G, Beeckman T (2009) Receptor-like kinases shape the plant. Nat Cell Biol 11:1166–1173

  14. Dievart A, Clark SE (2004) LRR-containing receptors regulating plant development and defense. Development 131:251–261

  15. Dougherty GW, Jose C, Gimona M, Cutler ML (2008) The Rsu-1-PINCH1-ILK complex is regulated by Ras activation in tumor cells. Eur J Cell Biol 87:721–734

  16. Eitas TK, Dangl JL (2010) NB-LRR proteins: pairs, pieces, perception, partners, and pathways. Curr Opin Plant Biol 13(4):472–477

  17. Fluhr R (2001) Sentinels of disease. Plant resistance genes. Plant Physiol 127:1367–1374

  18. Forsthoefel NR, Cutler K, Port MD, Yamamoto T, Vernon DM (2005) PIRLs: a novel class of plant intracellular leucine-rich repeat proteins. Plant Cell Physiol 46:913–922

  19. Forsthoefel NR, Dao TP, Vernon DM (2010) PIRL1 and PIRL9, encoding members of a novel plant-specific family of leucine-rich repeat proteins, are essential for differentiation of microspores into pollen. Planta 232(5):1101–1114

  20. Hellmann H, Estelle M (2002) Plant development: regulation by protein degradation. Science 297:793–797

  21. Jeong KW, Lee YH, Stallcup MR (2009) Recruitment of the SWI/SNF chromatin remodeling complex to steroid hormone-regulated promoters by nuclear receptor coactivator flightless-I. J Biol Chem 284:29298–29309

  22. Johnson-Brousseau SA, McCormick S (2004) A compendium of methods useful for characterizing Arabidopsis pollen mutants and gametophytically-expressed genes. Plant J 39:761–775

  23. Lee YH, Campbell HD, Stallcup MR (2004) Developmentally essential protein flightless I is a nuclear receptor coactivator with actin binding activity. Mol Cell Biol 24:2103–2117

  24. Li W, Han M, Guan KL (2000) The leucine-rich repeat protein SUR-8 enhances MAP kinase activation and forms a complex with Ras and Raf. Genes Dev 14:895–900

  25. McHale L, Tan X, Koehl P, Michelmore RW (2006) Plant NBS-LRR proteins: adaptable guards. Genome Biol 7:212

  26. Morillo SA, Tax FE (2006) Functional analysis of receptor-like kinases in monocots and dicots. Curr Opin Plant Biol 9:460–469

  27. Morris ER, Walker JC (2003) Receptor-like protein kinases: the keys to response. Curr Opin Plant Biol 6:339–342

  28. Preuss D, Rhee SY, Davis RW (1994) Tetrad analysis possible in Arabidopsis with mutation of the QUARTET (QRT) genes. Science 264:1458–1460

  29. Sieburth DS, Sun Q, Han M (1998) SUR-8, a conserved Ras-binding protein with leucine-rich repeats, positively regulates Ras-mediated signaling in C. elegans. Cell 94:119–130

  30. Somers DE, Fujiwara S (2009) Thinking outside the F-box: novel ligands for novel receptors. Trends Plant Sci 14:206–213

  31. Sternberg PW, Alberola-Ila J (1998) Conspiracy theory: RAS and RAF do not act alone. Cell 95:447–450

  32. Tax FE, Vernon DM (2001) T-DNA-associated duplication/translocations in Arabidopsis. Implications for mutant analysis and functional genomics. Plant Physiol 126:1527–1538

  33. Vernon DM, Forsthoefel NR (2002) Leucine-rich repeat proteins in plants: diverse roles in signaling and development. In: Pandali SG (ed) Research signpost: recent research developments in plant biology, pp 202–214

  34. Winter D, Vinegar B, Nahal H, Ammar R, Wilson GV et al (2007) An electronic fluorescent pictograph browser for exploring and analyzing large-scale biological data sets. PLoS ONE 2(8):e718

  35. Zimmermann P, Hirsch-Hoffmann M, Hennig L, Gruissem W (2004) GENEVESTIGATOR. Arabidopsis microarray database and analysis toolbox. Plant Physiol 136:2621–2632

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This work was supported by NSF award 0616166 to D.M.V. Whitman College’s SEM facility was provided by NSF grant 0922978. We thank Thuy Dao for assistance with PCR and phenotype analyses, and Michelle Shafer and Caroline Reinhart for assistance with SEM. Caroline Reinhart was supported in part by a Voyles summer research scholarship, provided by a gift to Whitman College.

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Correspondence to Daniel M. Vernon.

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Forsthoefel, N.R., Vernon, D.M. Effect of sporophytic PIRL9 genotype on post-meiotic expression of the Arabidopsis pirl1;pirl9 mutant pollen phenotype. Planta 233, 423–431 (2011). https://doi.org/10.1007/s00425-010-1324-5

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  • Arabidopsis thaliana
  • Gametophyte
  • Gene knockout
  • Genetic redundancy
  • Paternal effect
  • Pollen development