Habituated embryogenic line of pumpkin contained more CKs and IAA, but less ABA than the non-habituated line. Pronounced hypomethylation correlated with the absence of 2,4-D, addition of 5-azaC, and the process of habituation. A comparative analysis between habituated and non-habituated embryogenic cultures of pumpkin (Cucurbita pepo L.) in relation to endogenous phytohormones, global DNA methylation, and developmental and regeneration capacities of the cultures was conducted. The analysis revealed more cytokinins (CKs) and indole-3-acetic acid (IAA), but less abscisic acid (ABA) in the habituated HEC line than in the non-habituated DEC line. Ribosides and ribotides were the most abundant CK forms in both HEC and DEC lines (75.9 and 57.6 %, respectively). HEC contained more free-base CKs (5.8 vs. 3.2 %), whereas DEC contained considerably more O-glycosides (39.1 vs. 18.3 %). Although prevalence of IAA was common for both lines, relative ratio of CKs and ABA differed between DEC and HEC lines. ABA was prevailing over CKs in DEC, while CKs prevailed over ABA in HEC line. Taking into account the importance of ABA for embryo maturation, the reduced endogenous ABA content in HEC line might be the reason for a 5-fold reduction in regeneration capacity compared to DEC. Both habituated and non-habituated embryogenic lines were highly methylated in the presence of 2,4-dichlorophenoxyacetic acid (2,4-D). Pronounced hypomethylation correlated with the absence of 2,4-D, addition of 5-azacytidine (5-azaC), but also with the process of habituation. The habituated line was resistant to the effect of hypomethylation drug 5-azaC and remained highly methylated even after the addition of 5-azaC. Also, 5-azaC did not change the developmental pattern in the habituated line, indicating the existence of separate mechanisms by which 2,4-D influences global DNA methylation in comparison to habituation-related global DNA methylation.

Faculty of Science University of Zagreb Horvatovac 102a 10000 Zagreb Croatia

Institute Ruđer Bošković Bijenička cesta 54 10000 Zagreb Croatia

Laboratory of Growth Regulators Centre of the Region Haná for Biotechnological and Agricultural Research Palacký University and Institute of Experimental Botany ASCR Šlechtitelů 11 783 71 Olomouc Czech Republic

Zobrazit více v PubMed

Theor Appl Genet. 1989 Mar;77(3):325-31 PubMed

Nucleic Acids Res. 1977;4(5):1257-65 PubMed

Dev Growth Differ. 2010 Aug;52(6):555-66 PubMed

Planta. 2006 Mar;223(4):637-45 PubMed

J Plant Physiol. 2004 Feb;161(2):229-36 PubMed

Trends Plant Sci. 2000 Dec;5(12):506-8 PubMed

Biochim Biophys Acta. 2011 Aug;1809(8):444-51 PubMed

Plant Physiol. 2006 Apr;140(4):1255-78 PubMed

Plant Physiol Biochem. 2005 Jul;43(7):681-91 PubMed

New Phytol. 2010 Jun;186(4):856-68 PubMed

Cancer Res. 1983 Feb;43(2):763-9 PubMed

Anal Biochem. 1964 Dec;9:431-42 PubMed

Nat Rev Genet. 2010 Mar;11(3):204-20 PubMed

Plant Cell. 2006 Apr;18(4):805-14 PubMed

Annu Rev Genet. 1989;23:395-408 PubMed

Plant Physiol. 2002 Aug;129(4):1807-19 PubMed

Plant Cell Rep. 2004 Sep;23(3):120-7 PubMed

Plant Cell Physiol. 2012 May;53(5):766-84 PubMed

Comp Biochem Physiol C Toxicol Pharmacol. 2014 Mar;160:54-9 PubMed

Development. 2003 Dec;130(25):6201-8 PubMed

Curr Top Dev Biol. 2004;60:55-89 PubMed

Nat Rev Genet. 2005 May;6(5):351-60 PubMed

Talanta. 2009 Dec 15;80(2):651-5 PubMed

Plant Cell Rep. 1991 Mar;9(11):623-6 PubMed

Plant Sci. 2000 Dec 7;160(1):15-26 PubMed

Talanta. 2009 Nov 15;80(1):390-9 PubMed

PLoS Genet. 2011 Aug;7(8):e1002243 PubMed

Genome. 1996 Apr;39(2):235-42 PubMed

Oncogene. 2002 Aug 12;21(35):5483-95 PubMed

J Chromatogr B Analyt Technol Biomed Life Sci. 2007 Mar 1;847(2):162-73 PubMed

Nat Rev Mol Cell Biol. 2011 Jul 22;12(8):483-92 PubMed

Phytochemistry. 2008 Aug;69(11):2214-24 PubMed

Int Rev Cytol. 2004;233:135-79 PubMed

Dev Genet. 1989;10(4):298-303 PubMed

Am J Bot. 2004 Nov;91(11):1743-56 PubMed

Temperature and Water Availability During Maturation Affect the Cytokinins and Auxins Profile of Radiata Pine Somatic Embryos

5-Azacytidine mediated reactivation of silenced transgenes in potato (Solanum tuberosum) at the whole plant level