1. Full name: Phạm Thu Hằng                                         2. Sex: Female

3. Date of birth: 24/12/1984                                            4. Place of birth: Phu Tho

5. Admission decision number: Decision No. 2934/QĐ-KHTN-CTSV, dated on 07/9/2011 by President of Vietnam National University, Hanoi

6. Changes in academic process: Changing supervisor under Decision No 3385/QĐ-ĐHKHTN, dated on 08/9/2015 by Rector of VNU University of Science

7. Official thesis title: Generation of transgenic rice lines encoding the NAC transcription factor associated for drought stress tolerance.

8. Major: Biochemistry                                                   9. Code: 62 42 01 16

10. Supervisors: Assoc.Prof.Dr. Pham Xuan Hoi

11. Summary of the new findings of the thesis

- Three ORFs namely OsNAC1, OsNAC5 and OsNAC10 were successfully isolated , sequenced from drought stress-treated cDNA of Vietnam rice cultivar and cloned into pGEM-T vector. The isolated gene sequences were alternately 951 bp, 993 bp _1182 bp in length and homology with published genes at 99% (compared with homologous gene ID AY596808.1), 98% (AB028184.1) , 92% (AK069257.1) sequently from Nipponbare, a japonica rice cultivar. Analysis of its deduced amino acid sequence indicated that this protein contains conserve domains and one putative nuclear localization signal at N-terminal like all well-known NAC proteins. The expression analysis results showed that these transcriptions were  up-regulated by drought stress treatment.

- The OsNAC1 over-expression constructs driven by promoters namely constitutive 35S, Ubiquitin, stress-inducible Lip9 and Rd29A were generated. These constructs were successfully transformed into A. tumefaciens strain LBA4404.

- These constructs named Lip9:OsNAC1:Nos and Ubi:OsNAC1:Nos were successfully transferred into J02 rice variety/cultivar. The presence of the putative positive transgene was confirmed by PCR. The qRT-PCR was then used for estimating the number of target gene  copies and homozygous in transgenic rice lines. The expression of transformed  OsNAC1in T2 putative transgenic rice lines was detected  by RT-PCR.

- Evaluation the growth, development by agronomic indicators (eg. plant height, number of branches, number of seeds/ cornflower, seed to seed  period); Estimation  drought tolerance of transgenic lines by physiological (relative water content, chlorophyll content) and biochemical (proline content, oxidation activator production). Two transgenic rice lines expressed the Ubi:OsNAC1:Nos and three transgenic rice lines expressed the Lip9: OsNAC1:Nos have the same growth capacity as the control plants under normal conditions. Under drought stress conditions, transgenic rice lines have morphological, physiological and biochemical indicators showing higher drought tolerance than control rice lines in reproductive age. At the same time, the survival rate of the transgenic lines was higher than that of the control lines at drought. Specifically, transgenic lines L1.1, L4.2, U6.1, L5.1, U4.2 had survival rates of 90%, 84%, 81%, 67%, 62%, while WT plants had survival rates only 53%.

12. Practical applicability, if any:

The results of this thesis have generated T2 rice lines carrying a copy of the OsNAC1 gene in homozygous form under the control of the driven stress-inducible Lip9 promoter and continuous Ubi promoter. Transgenic plants have the same phenotype with WT plants (in terms of growth, development and yield) under normal conditions, while tolerance to drought and high survival rates more in terms of drought stress treatment. This is an important result, demonstrating the potential application of the OsNAC1 gene in particular and the transcriptional gene encoding genomes of the NAC group in relation not only to the general stress responses, but also to drought tolerant transgenic plants. Based on the our results of the thesis, OsNAC1 gene expression vectors produced by the thesis are being transformedinto other important cultivars such as maize, cotton, soybean... to produce drought tolerant transgenic plants, to meet the urgent needs of production in the context of global climate changing in Vietnam.

13. Further research directions, if any:

- Analysis continously the expression of OsNAC1 gene in the generation of T2 and T3 transgenic lines  in order to identify the role of the gene  in other abiotic stress responses.

- Transformation  OsNAC1 gene the constructs haboring the target gene driven by the stress-inducible promoters, into the different agricultural crops .

14. The publications:

Pham Thu Hang, Nguyen Duy Phuong và Pham Xuan Hoi (2014), “Isolation of OsNAC10 gene involved in stress tolerance from Indica rice”. Journal of Biotechnology 12(2): 319-326.

Nguyen Duy Phuong, Pham Thu Hang và Pham Xuan Hoi (2014), “Isolation of OsNAC5 gene involved in stress tolerance from Indica rice”. VNU Journal of Science: Natural Sciences and Technology 30(4):40-47.

Pham Thu Hang, Nguyen Duy Phuong, Tran Lan Đai, Phan Tuan Nghia và Pham Xuan Hoi (2014), “Constrution of expression vector containing OsNAC1 driven by stress-inducible RD29A promoter”. VNU Journal of Science: Natural Sciences and Technology 30(4):1-10.

Pham Thu Hang, Nguyen Duy Phuong, Phan Tuan Nghia, Pham Xuan Hoi (2016), “Study on genetic transformation of Japonica rice with drought-responsive OsNAC1 gene”. Science and technology journal of Agriculture & Rural development 1: 17-22.

Pham Thu Hang, Đam Quang Hieu, Phan Tuan Nghia, Pham Xuan Hoi (2016), “Construction of  vector and transformation of drought-responsive gene OsNAC1 into J02 (Oryza sativa L. japonica). Journal of Biotechnology 14(2): 271 – 277.

Cao Le Quyen, Pham Thu Hang, Pham Xuan Hoi (2017), “Estimating the number of transgene copies and homozygous in OsNAC1 transgenic rice by quantitative real-time PCR assay”. Journal of Vietnam Agricultural science and technology 5(78): 83-87.