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| Author(s): |
Max Seiji Tsunada
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | Campinas, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Instituto de Biologia |
| Defense date: | 2018-08-28 |
| Examining board members: |
Marcelo Menossi;
Alessandra Alves de Souza;
Carlos Takeshi Hotta;
Igor Cesarino;
Monalisa Sampaio Carneiro
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| Advisor: | Marcelo Menossi |
| Abstract | |
Drought is one of the main limiting factors for agricultural productivity and its effects are likely to be more intense in some land areas, according to climate change models. In this context, the understanding of regulatory mechanisms activated by plants in response to adverse environmental conditions may help to develop stress tolerant crops. Recently, genetic changes in the root system have been highlighted as an opportunity for plant breeding. Additionally, the use of inducible and organ specific promoters may help in the fine tuning of transgene expression. Therefore, the aim of this study was to characterize the regulatory activity of promoters from genes induced by drought and/or root-specific and their biotechnological potential in sugarcane transgenic plants. The promoter sequences were fused to "GUS" gene reporter to track their regulatory activity. Induction by drought and root-preferential regulation were detected in transgenic events via qPCR of the GUS transcript. However, no GUS activity was detected in plants submitted to GUS histochemical assay, indicating a probable post-transcriptional silencing event. In order to test this hypothesis and solve this issue, we generated a new construction composed by the promoter "ScDHN1" controlling the transcription of "scoGUS" gene, a codon-optimized GUS sequence for sugarcane. The use of "scoGUS" enabled to detect the promoter "ScDHN1" activity in plantlets under osmotic stress in vitro, while in the same conditions no activity was detected for plantlets harboring the native "GUS" gene from Escherichia coli. We also performed a genomic identification of the dehydrin family in sugarcane, and the influence of drought on the transcriptional regulation of "ScDHN" genes. Our data support that dehydrin members might play protective roles in sugarcane under hydric deficit. Lastly, new sugarcane promoter sequences displaying drought-inducible and/or root-preferential profile were characterized aiming biotechnology applications. The data provided in this work will also be useful for basic studies with regulatory sequence in sugarcane, in which the use of codon-optimized reporter genes is essential (AU) | |
| FAPESP's process: | 16/05501-6 - Promoters, cis regulatory elements and transcription factors involved in drought responses in sugarcane roots (Saccharum spp.) |
| Grantee: | Max Seiji Tsunada |
| Support Opportunities: | Scholarships in Brazil - Doctorate (Direct) |