Rasika Lasanthi-Kudahettige

Publications (2)9.03 Total impact

• Source

  Available from: Pierdomenico Perata

  Article: Expansin gene expression and anoxic coleoptile elongation in rice cultivars.

  Leonardo Magneschi, Rasika Lasanthi Kudahettige, Amedeo Alpi, Pierdomenico Perata
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  ABSTRACT: Coleoptiles of rice seeds that germinate under anoxia usually elongate to a length far exceeding the elongation that takes place under aerobic conditions. It has been suggested that expansins play a role in this process, but studies examining correlations between transcript levels of expansin genes and anoxic growth of rice coleoptiles are limited. In this study, we used real-time quantitative PCR (qPCR) analysis to develop a picture of expansin gene expression (seven alpha- and eight beta-expansins) (EXPA and EXPB) in two rice cultivars showing long (cv. Arborio Precoce) or short (cv. Lamone) coleoptiles when germinated under anoxia. Our qPCR analysis suggested up-regulation occurred for several expansin genes in anoxic coleoptiles in both rice cultivars. However, we found no correlation between transcript levels and the ability to elongate the coleoptile under anoxia.
  Journal of plant physiology 05/2009; 166(14):1576-80. · 2.50 Impact Factor
• Article: Transcript profiling of the anoxic rice coleoptile.

  Rasika Lasanthi-Kudahettige, Leonardo Magneschi, Elena Loreti, Silvia Gonzali, Francesco Licausi, Giacomo Novi, Ottavio Beretta, Federico Vitulli, Amedeo Alpi, Pierdomenico Perata
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  ABSTRACT: Rice (Oryza sativa) seeds can germinate in the complete absence of oxygen. Under anoxia, the rice coleoptile elongates, reaching a length greater than that of the aerobic one. In this article, we compared and investigated the transcriptome of rice coleoptiles grown under aerobic and anaerobic conditions. The results allow drawing a detailed picture of the modulation of the transcripts involved in anaerobic carbohydrate metabolism, suggesting up-regulation of the steps required to produce and metabolize pyruvate and its derivatives. Sugars appear to play a signaling role under anoxia, with several genes indirectly up-regulated by anoxia-driven sugar starvation. Analysis of the effects of anoxia on the expansin gene families revealed that EXPA7 and EXPB12 are likely to be involved in rice coleoptile elongation under anoxia. Genes coding for ethylene response factors and heat shock proteins are among the genes modulated by anoxia in both rice and Arabidopsis (Arabidopsis thaliana). Identification of anoxia-induced ethylene response factors is suggestive because genes belonging to this gene family play a crucial role in rice tolerance to submergence, a process closely related to, but independent from, the ability to germinate under anoxia. Genes coding for some enzymes requiring oxygen for their activity are dramatically down-regulated under anoxia, suggesting the existence of an energy-saving strategy in the regulation of gene expression.
  Plant physiology 06/2007; 144(1):218-31. · 6.53 Impact Factor