Double-Stranded RNA-Mediated Downregulation of pdhk Gene Expression to Shorten Maturation Time of a Late Maturing Native indica Rice Cultivar, Badshahbhog

• Published in: Crop science 2012-07, Vol.52 (4), p.1743-1753
• Main Authors: Mukherjee, Rajeswari, Gayen, Srimonta, Chakraborty, Anirban, Bhattacharyya, Jagannath, Maiti, Mrinal K, Basu, Asitava, Sen, Soumitra K
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Biological and medical sciences; cell respiration; Cultivars; Dehydrogenase; double-stranded RNA; energy; flowering; Fundamental and applied biological sciences. Psychology; gene expression; gene silencing; genes; Genetic engineering; Genetics and breeding of economic plants; inflorescences; Kinases; Northern blotting; Oryza sativa; phosphorylation; Proteins; pyruvate dehydrogenase (acetyl-transferring) kinase; pyruvate dehydrogenase (lipoamide); quantitative polymerase chain reaction; reverse transcriptase polymerase chain reaction; Rice; Transgenic plants; tricarboxylic acid cycle
• ISSN: 1435-0653; 0011-183X; 1435-0653
• DOI: 10.2135/cropsci2011.07.0352

In eukaryotic organisms, pyruvate dehydrogenase kinase (PDHK) plays a significant role in the Krebs cycle, cellular respiration, and energy production by regulating the mitochondrial pyruvate dehydrogenase complex (mtPDC) via reversible phosphorylation. The present study reports pdhk gene downregulation effects on maturation time of a late maturing, aromatic, native indica rice (Oryza sativa L.) cultivar, Badshahbhog. A double-stranded ribonucleic acid (dsRNA)-mediated gene silencing strategy was used to downregulate rice mitochondrial pdhk gene expression. The transgenic plant lines displayed altered growth patterns--early flower initiation, increased grain formation per panicle, and -10 d earlier maturation--compared to a nontransformed cultivar. Northern blot, reverse transcription-polymerase chain reaction (RT-PCR), and real-time polymerase chain reaction (PCR) analyses provided evidence for endogenous pdhk gene downregulation in T0, T1, and T2 generations of transgenic rice lines. These results provided evidence for stable pdhk gene downregulation throughout filial generations. It was further observed that transgenic lines with two insertion events of transferred dsRNA effected more downregulation of pdhk gene expression relative to rice lines carrying a single dsRNA insertion.