Abstract
Bioactive gibberellins (GAs) are phytohormones that regulate plant growth and development. DELLA proteins are highly conserved growth repressors that modulate all aspects of GA responses. In this study, an apple MhGAI2 gene, which encoded a DELLA protein, was isolated from the tea crabapple (Malus hupehensis Redh. var. pingyiensis). MhGAI2-GFP fusion protein was localized in the nucleus. Anti-MhGAI2 antibody was prepared to test GA sensitivity of the MhGAI2 protein. To elucidate the function of MhGAI2, its GA-insensitive gene mhgai2 was artificially generated via a bridge-PCR approach. Subsequently, mhgai2 was genetically transformed into tomato, while transgenic tomato line pBI containing the empty vector pBI121 was used as control. Transgenic tomato lines TL1 and TL2 ectopically expressed mhgai2 transcripts at high levels, and produced GA-insensitive mhgai2 protein. As a result, the seed germination as well as the growth of roots, hypocotyls and seedlings were much more insensitive to exogenous GA3 application in transgenic tomato lines TL1 and TL2 than pBI control. TL1 and TL2 exhibited smaller plant statures and produced more compacted inflorescences with smaller flowers, fruits and seeds than pBI control. Therefore, mhgai2 ectopic expression affected not only the vegetative growth but also the reproductive development of transgenic tomatoes. In addition, transgenic seedlings were more resistant to drought and salt stress than pBI. In summary, ectopic expression of apple mhgai2 gene caused GA-insensitive phenotypes in tomatoes.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Achard P, Cheng H, De Grauwe L, Decat J, Schoutteten H, Moritz T, Van Der Straeten D, Peng JR, Harberd NP (2006) Integration of plant responses to environmentally activated phytohormonal signals. Science 311:91–94
Achard P, Gong F, Cheminant S, Alioua M, Hedden P, Genschik P (2008) The cold-inducible CBF1 factor- dependent signaling pathway modulates the accumulation of the growth-repressing DELLA proteins via its effect on gibberellin metabolism. Plant Cell 20:2117–2129
Boss PK, Thomas MR (2002) Association of dwarfism and floral induction with a grape ‘green revolution’ mutation. Nature 416:847–850
Chandler PM, Poll AM, Ellis M, Gubler F (2002) Mutants at the Slender1 locus of barley cv Himalaya. molecular and physiological characterization. Plant Physiol 129:181–190
Cheng H, Qin L, Lee S, Fu XD, Richards DE, Cao DN, Luo D, Harberd NP, Peng JR (2004) Gibberellin regulates Arabidopsis floral development via suppression of DELLA protein function. Development 131:1055–1064
Dill A, T-p Sun (2001) Synergistic derepression of gibberellin signaling by removing RGA and GAI function in Arabidopsis thaliana. Genetics 159:777–785
Dill A, Thomas SG, Hu J, Steber CM, Sun T-p (2004) The Arabidopsis F-box protein SLEEPY1 targets gibberellin signaling repressors for gibberellin-induced degradation. Plant Cell 16:1392–1405
Ellul P, Garcia-Sogo B, Pineda B, Rios G, Roig L, Moreno V (2003) The ploidy level of transgenic plants in Agrobacterium-mediated transformation of tomato cotyledons (Lycopersicon esculentum Mill) is genotype and procedure dependent. Theor Appl Genet 106:231–238
Fleck B, Harberd P (2002) Evidence that the Arabidopsis nuclear gibberellin signalling protein GAI is not destabilised by gibberellin. Plant J 32:935–947
Fleet CM, T-p Sun (2005) A DELLAcate balance: the role of gibberellin in plant morphogenesis. Curr Opin Plant Biol 8:77–85
Foster T, Kirk C, Jones WT, Allan AC, Espley R, Karunairetnam S, Rakonjac J (2007) Characterisation of the DELLA subfamily in apple (Malus × domestica Borkh.). Tree Genet Genomes 3:187–197
Fu XD, Sudhakar D, Peng JR, Richards DE, Christou P, Harberd NP (2001) Expression of Arabidopsis GAI in transgenic rice represses multiple gibberellin responses. Plant Cell 13:1791–1802
Gomi K, Matsuoka M (2003) Gibberellin signalling pathway. Curr Opin Plant Biol 6:489–493
Gou JQ, Strauss SH, Tsai CJ, Fang K, Chen YR, Jiang XN, Busov VB (2010) Gibberellins Regulate Lateral Root Formation in Populus through Interactions with Auxin and Other Hormones. Plant Cell 22:623–639
Gubler F, Chandler PM, White RG, Llewellyn DJ, Jacobsen JV (2002) Gibberellin signaling in barley aleurone cells. control of SLN1 and GAMYB expression. Plant Physiol 129:191–200
Hynes LW, Peng JR, Richards DE, Harberd NP (2003) Transgenic expression of the Arabidopsis DELLA proteins GAI and gai confers altered gibberellin response in tobacco. Transgenic Res 12:707–714
Itoh H, Ueguchi-Tanaka M, Sato Y, Ashikari M, Matsuoka M (2002) The gibberellin signaling pathway is regulated by the appearance and disappearance of SLENDER RICE1 in nuclei. Plant Cell 14:57–70
Jasinski S, Tattersall A, Piazza P, Hay A, Martinez-Garcia JF, Schmitz G, Theres K, McCormick S, Tsiantis M (2008) PROCERA encodes a DELLA protein that mediates control of dissected leaf form in tomato. Plant J 56:603–612
King KE, Moritz T, Harberd NP (2001) Gibberellins are not required for normal stem growth in Arabidopsis thaliana in the absence of GAI and RGA. Genetics 159:767–776
Lawit SJ, Wych HM, Xu DP, Kundu S, Tomes DT (2010) Maize DELLA proteins dwarf plant8 and dwarf plant9 as modulators of plant development. Plant Cell Physiol 51:1854–1868
Lee S, Cheng H, King KE, Wang W, He Y, Husssain A, Lo J, Harberd NP, Peng JR (2002) Gibberellin regulates Arabidopsis seed germination via RGL2, a GAI/RGA-like gene whose expression is up-regulated following imbibition. Genes Dev 16:646–658
Li DD, Shi W, Deng XX (2002) Agrobacterium-mediated transformation of embryogenic calluses of Ponkan mandarin and the regeneration of plants containing the chimeric ribonuclease gene. Plant Cell Rep 21:153–156
Magome H, Yamaguchi S, Hanada A, Kamiya Y, Oda K (2008) The DDF1 transcriptional activator upregulates expression of a gibberellin-deactivating gene, GA2ox7, under high-salinity stress in Arabidopsis. Plant J 56:613–626
Martí C, Orzaez D, Ellul P, Moreno V, Carbonell J, Granell A (2007) Silencing of DELLA induces facultative parthenocarpy in tomato fruits. Plant J 52:865–876
Muangprom A, Thomas SG, Sun T-p, Osborn TC (2005) A Novel Dwarfing Mutation in a Green Revolution Gene from Brassica rapa. Plant Physiol 137:931–938
Newcomb RD, Crowhurst RN, Gleave AP, Rikkerink EHA, Allan AC, Beuning LL, Bowen JH, Gera E, Jamieson KR, Janssen BJ, Laing WA, McArtney S, Nain B, Ross GS, Snowden KC, Souleyre EJF, Walton EF, Yauk Y-K (2006) Analyses of expressed sequence tags from apple (Malus x domestica). Plant Physiol 141:147–166
Ogawa M, Hanada A, Yamauchi Y, Kuwahara A, Kamiya Y, Yamaguchi S (2003) Gibberellin biosynthesis and response during Arabidopsis seed germination. Plant Cell 15:1591–1604
Peng JR, Carol P, Richards DE, King KE, Cowling RJ, Murphy GP, Harberd NP (1997) The Arabidopsis GAI gene defines a signaling pathway that negatively regulates gibberellin responses. Genes Dev 11:3194–3205
Peng JR, Richards DE, Hartley NM et al (1999) “Green revolution” Genes encode mutant gibberellin response modulators. Nature 400:256–261
Richards D, King KE, Ait-ali T, Harberd NP (2001) How gibberellin regulates plant growth and development: a molecular genetic analysis of gibberellin signaling. Annu Rev Plant Physiol Plant Mol Biol 52:67–88
Schwechheimer C (2008) Understanding gibberellic acid signaling—are we there yet? Curr Opin Plant Biol 11:9–15
Silverstone AL, Jung H-S, Dill A, Kawaide H, Kamiya Y, Sun T-p (2001) Repressing a repressor: gibberellin-induced rapid reduction of the RGA protein in Arabidopsis. Plant Cell 13:1555–1566
Street NR, Skogström O, Sjödin A, Tucker J, Rodríguez-Acosta M, Nilsson P, Jansson S, Taylor G (2006) The genetics and genomics of the drought response in Populus. Plant J 48:321–341
Thomas SG, T-p Sun (2004) Update on gibberellin signaling. A tale of the tall and the short. Plant Physiol 135:668–676
T-p Sun, Gubler F (2004) Molecular mechanism of gibberellin signaling in plants. Annu Rev Plant Biol 55:197–223
Tyler L, Thomas SG, Hu J, Dill A, Alonso JM, Ecker JR, Sun T-p (2004) DELLA proteins and gibberellin-regulated seed germination and floral development in Arabidopsis. Plant Physiol 135:1008–1019
Wang F, Zhu DM, Huang X, Li S, Gong YN et al (2009) Biochemical insights on degradation of Arabidopsis DELLA proteins gained from a cell-free assay system. Plant Cell 21:2378–2390
Wen CK, Chang C (2002) Arabidopsis RGL1 encodes a negative regulator of gibberellin responses. Plant Cell 14:87–100
Willige BC, Ghosh S, Nill C, Zourelidou M, Dohmann EMN, Maier A, Schwechheimer C (2007) The DELLA domain of GA INSENSITIVE mediates the interaction with the GA INSENSITIVE DWARF1A Gibberellin receptor of Arabidopsis. Plant Cell 19:1209–1220
Zhu LH, Li XY, Welander M (2008) Overexpression of the Arabidopsis gai gene in apple significantly reduces plant size. Plant Cell Rep 27:289–296
Acknowledgments
This work was supported by the Ministry of Science and Technology (2007CB947604) and NSFC (30771499), National High Technology Research and Development Program of China (2011AA100204) and ‘‘Taishan Scholar’’ project from Shandong Province of China.
Author information
Authors and Affiliations
Corresponding author
Additional information
Communicated by Z.-L. Zhang.
S.-S. Wang and C. Sun contributed equally to this work.
Rights and permissions
About this article
Cite this article
Wang, SS., Sun, C., Liu, ZZ. et al. Ectopic expression of the apple mhgai2 gene brings about GA-insensitive phenotypes in tomatoes. Acta Physiol Plant 34, 2369–2377 (2012). https://doi.org/10.1007/s11738-012-1041-8
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11738-012-1041-8