title: RNAi silencing of three homologues of S-adenosylmethionine decarboxylase gene in tapetal tissue of tomato results in male sterility.
abstract: Polyamines play very important role in various cellular metabolic functions, including floral induction, floral differentiation and fertility regulation. In the present study, S-adenosylmethionine decarboxylase (SAMDC), a key gene involved in polyamine biosynthesis, has been targeted in tapetal tissue of tomato using RNAi to examine its effect on tapetum development and pollen viability. The target SAMDC gene fragments of three homologues were cloned in a hairpin RNA construct under the control of tapetal-specific A9 promoter, which was used to generate several RNAi tomato plants. These RNAi lines expressed the intended small interfering RNAs in the anther and showed the aborted and sterile pollen exhibiting shrunken and distorted morphology. These RNAi tomato plants having sterile pollen, failed to set fruits but female fertility of the plants remained unaffected as cross pollination resulted in fruit setting. Expression profiling of SAMDC genes showed considerable decrease in transcripts of SAMDC1 (5-8 fold) and SAMDC2 and SAMDC3 (2-3 fold) in the anthers of RNAi plants. The other polyamine biosynthesis genes, ADC and SPDSYN exhibited ~1.5 fold decrease in their transcript levels. Presence of siRNA molecules specific to SAMDC homologues in anther and tapetal-specific activity of A9 promoter as shown with GUS reporter system of RNAi plants suggested down-regulation of the target genes in tapetum by RNAi. These observations indicate the importance of SAMDC, in turn polyamines in pollen development, and thus tapetum-specific down-regulation of SAMDC genes using RNAi can be used for developing male sterile plants.
authors.affiliation: Plant Polyamine, Transgenic and RNAi Laboratory, Department of Genetics, University of Delhi, South Campus, Benito Juarez Road, New Delhi, 110021, India.
authors.forename: Ranjita
authors.initials: R
authors.lastname: Sinha
authors.forename: Manchikatla Venkat
authors.initials: MV
authors.lastname: Rajam
mesh_terms: D012437:Adenosylmethionine Decarboxylase / Q000235:genetics*; D017360:Arabidopsis / Q000235:genetics; D001483:Base Sequence; D015536:Down-Regulation / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant / Q000235:genetics*; D018551:Solanum lycopersicum / Q000201:enzymology* / Q000235:genetics* / Q000648:ultrastructure; D051479:Plant Infertility / Q000235:genetics*; D030821:Plants, Genetically Modified; D011058:Pollen / Q000201:enzymology* / Q000235:genetics / Q000648:ultrastructure; D011073:Polyamines / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000235:genetics; D034622:RNA Interference; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013489:Suppression, Genetic
chemical_list: D011073:Polyamines; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D012437:Adenosylmethionine Decarboxylase
references.citation: J Integr Plant Biol. 2012 Feb;54(2):115-30
references.pmid: 22221327
references.citation: Cell. 1980 Nov;22(2 Pt 2):603-9
references.pmid: 7192606
references.citation: Trends Biotechnol. 2010 Jan;28(1):3-8
references.pmid: 19857909
references.citation: Annu Rev Plant Biol. 2005;56:393-434
references.pmid: 15862102
references.citation: Plant Cell. 2004;16 Suppl:S84-97
references.pmid: 15075396
references.citation: J Plant Physiol. 2004 Jun;161(6):709-13
references.pmid: 15266718
references.citation: Front Plant Sci. 2012 Aug 17;3:180
references.pmid: 22912643
references.citation: Plant Cell. 1992 Mar;4(3):253-62
references.pmid: 1498595
references.citation: Plant Biotechnol J. 2010 Dec;8(9):1005-22
references.pmid: 21050365
references.citation: Plant Physiol Biochem. 2010 Jul;48(7):565-73
references.pmid: 20359902
references.citation: Methods. 2007 Oct;43(2):110-7
references.pmid: 17889797
references.citation: Int J Biochem Cell Biol. 2010 Jan;42(1):39-51
references.pmid: 19643201
references.citation: Stain Technol. 1970 May;45(3):115-20
references.pmid: 4192549
references.citation: Plant Biotechnol J. 2007 Mar;5(2):297-312
references.pmid: 17309685
references.citation: Plant J. 2008 Oct;56(1):132-45
references.pmid: 18557837
references.citation: Plant Cell Rep. 2012 Apr;31(4):747-56
references.pmid: 22120011
references.citation: J Plant Res. 2007 May;120(3):345-50
references.pmid: 17351711
references.citation: Nature. 1998 Feb 19;391(6669):806-11
references.pmid: 9486653
references.citation: Plant Physiol. 1990 Jun;93(2):439-45
references.pmid: 16667485
references.citation: Metabolites. 2012 Aug 20;2(3):516-28
references.pmid: 24957645
references.citation: Plant Cell Physiol. 2005 May;46(5):699-715
references.pmid: 15792960
references.citation: Plant Cell Physiol. 1995 Apr;36(3):487-94
references.pmid: 7757338
references.citation: Plant Mol Biol. 2003 May;52(2):247-58
references.pmid: 12856933
references.citation: Plant J. 2009 Apr;58(2):246-59
references.pmid: 19077165
references.citation: Trends Plant Sci. 2005 Dec;10(12):610-4
references.pmid: 16290216
references.citation: Plant Physiol. 1996 Nov;112(3):1343-1348
references.pmid: 12226449
references.citation: Plant J. 2010 Sep;63(6):1042-53
references.pmid: 20626657
references.citation: Plant Cell Physiol. 2006 Jun;47(6):784-7
references.pmid: 16565524