title: Solanum tuberosum StCDPK1 is regulated by miR390 at the posttranscriptional level and phosphorylates the auxin efflux carrier StPIN4 in vitro, a potential downstream target in potato development.
abstract: Among many factors that regulate potato tuberization, calcium and calcium-dependent protein kinases (CDPKs) play an important role. CDPK activity increases at the onset of tuber formation with StCDPK1 expression being strongly induced in swollen stolons. However, not much is known about the transcriptional and posttranscriptional regulation of StCDPK1 or its downstream targets in potato development. To elucidate further, we analyzed its expression in different tissues and stages of the life cycle. Histochemical analysis of StCDPK1::GUS (β-glucuronidase) plants demonstrated that StCDPK1 is strongly associated with the vascular system in stems, roots, during stolon to tuber transition, and in tuber sprouts. In agreement with the observed GUS profile, we found specific cis-acting elements in StCDPK1 promoter. In silico analysis predicted miR390 to be a putative posttranscriptional regulator of StCDPK1. Quantitative real time-polymerase chain reaction (qRT-PCR) analysis showed ubiquitous expression of StCDPK1 in different tissues which correlated well with Western blot data except in leaves. On the contrary, miR390 expression exhibited an inverse pattern in leaves and tuber eyes suggesting a possible regulation of StCDPK1 by miR390. This was further confirmed by Agrobacterium co-infiltration assays. In addition, in vitro assays showed that recombinant StCDPK1-6xHis was able to phosphorylate the hydrophilic loop of the auxin efflux carrier StPIN4. Altogether, these results indicate that StCDPK1 expression is varied in a tissue-specific manner having significant expression in vasculature and in tuber eyes; is regulated by miR390 at posttranscriptional level and suggest that StPIN4 could be one of its downstream targets revealing the overall role of this kinase in potato development.
authors.affiliation: Instituto de Investigaciones en Ingeniería Genética y Biología Molecular (INGEBI), CONICET and Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Vuelta de Obligado 2490 2do piso, 1428 Buenos Aires, Argentina.
authors.forename: Franco
authors.initials: F
authors.lastname: Santin
authors.affiliation: Biology Division, Indian Institute of Science Education and Research (IISER), Dr Homi Bhabha Road, Pune, Maharashtra 411008, India.
authors.forename: Sneha
authors.initials: S
authors.lastname: Bhogale
authors.affiliation: Instituto de Investigaciones en Ingeniería Genética y Biología Molecular (INGEBI), CONICET and Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Vuelta de Obligado 2490 2do piso, 1428 Buenos Aires, Argentina.
authors.forename: Elisa
authors.initials: E
authors.lastname: Fantino
authors.affiliation: Instituto de Investigaciones en Ingeniería Genética y Biología Molecular (INGEBI), CONICET and Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Vuelta de Obligado 2490 2do piso, 1428 Buenos Aires, Argentina.
authors.forename: Carolina
authors.initials: C
authors.lastname: Grandellis
authors.affiliation: Biology Division, Indian Institute of Science Education and Research (IISER), Dr Homi Bhabha Road, Pune, Maharashtra 411008, India.
authors.forename: Anjan K
authors.initials: AK
authors.lastname: Banerjee
authors.affiliation: Instituto de Investigaciones en Ingeniería Genética y Biología Molecular (INGEBI), CONICET and Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Vuelta de Obligado 2490 2do piso, 1428 Buenos Aires, Argentina.
authors.forename: Rita M
authors.initials: RM
authors.lastname: Ulloa
mesh_terms: D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D017930:Genes, Reporter; D007210:Indoleacetic Acids / Q000378:metabolism; D026901:Membrane Transport Proteins; D035683:MicroRNAs / Q000235:genetics*; D009928:Organ Specificity; D010766:Phosphorylation; D010937:Plant Growth Regulators / Q000378:metabolism; D018515:Plant Leaves / Q000166:cytology / Q000201:enzymology / Q000235:genetics; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000166:cytology / Q000201:enzymology / Q000235:genetics; D035281:Plant Tubers / Q000166:cytology / Q000201:enzymology / Q000235:genetics; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic / Q000235:genetics; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism*; D012323:RNA Processing, Post-Transcriptional; D018749:RNA, Plant / Q000235:genetics; D011198:Solanum tuberosum / Q000166:cytology / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D017871:Calcium-Calmodulin-Dependent Protein Kinases
chemical_list: D007210:Indoleacetic Acids; D026901:Membrane Transport Proteins; D035683:MicroRNAs; D010937:Plant Growth Regulators; D010940:Plant Proteins; D011494:Protein Kinases; D018749:RNA, Plant; D017871:Calcium-Calmodulin-Dependent Protein Kinases