GM lab focuses on the following research areas

 1. Epigenetic regulation of ribosomal RNA (rRNA) gene regulation and genomic instability in plants.

For this topic, we mainly use Arabidopsis thaliana as a model system, but we are extending our studies to rice (Oryza sativa) model system.

Funding:

DST-SERB, Government of India,

BITS-Pilani, Hyderabad campus

(Several hundred lines of Arabidopsis and gene constructs received as Kind Gift from the laboratory of Prof. Craig S. Pikaard, Hughes Medical Institute, Indiana University, Bloomington, USA.)

Relevant publications (GM as first or coauthor or corresponding author):

1. Gireesha Mohannath*, Anastasia McKinlay^#, Navinchandra Venkata Puppala^#, Ramya Enganti^#, Gargi Prasad Saradadevi^#, Todd Blevins and Craig S. Pikaard*. DNA hypermethylation and condensed chromatin correlate with chromosome-specific rRNA gene silencing in Arabidopsis.https://www.biorxiv.org/content/10.1101/2023.02.03.526984v1

(* Corresponding author; # equal contribution)

2. Gargi Prasad Saradadevi^#, Dalen Fultz^#, Murali Krishna Ramgopal^#, Abirami T. Subramanian, Gerin Prince, Vivek Thakur, and Gireesha Mohannath*. (2023). Structural variation among assembled genomes facilitates development of rapid and low-cost NOR-linked markers and NOR-telomere junction mapping in Arabidopsis. Plant Cell Reports 42, 1059-1069. 

3. Gargi Prasad Saradadevi, Abirami T. Subramanian^#, Shryli Kedambadi Shreekar^#, and Gireesha Mohannath*. (2023). Characterization of a new histone deacetylase 6 (hda6-11) mutant allele in Arabidopsis thaliana. Journal of Plant Biochemistry and Biotechnology. (2023). DOI: 10.1007/s13562-023-00831-7. 

(*Corresponding author; # equal contribution)

4. Gargi Prasad Saradadevi#., Neha Priyadarshini#, Aveepsha Bera# and Gireesha Mohannath*.(2020). Together we are on; together we are off- A conserved rule for ribosomal RNA (rRNA) gene regulation? Journal of Plant Biochemistry and Biotechnology. 29(4):743-753.

(* Corresponding author; # equal contribution)

5. Gireesha Mohannath, Frederic Pontvianne and Craig S. Pikaard. (2016). Selective nucleolus organizer inactivation in Arabidopsis is a chromosomal position-effect phenomenon. (2016). Proc. Natl. Acad. Sci. USA 137(47): 13426-13431.

6. Chinmayi Chandrasekhara, Gireesha Mohannath, Todd Blevins, Frederic Pontvianne and Craig S. Pikaard. (2016). Chromosome-specific NOR inactivation accounts for selective rRNA gene silencing and dosage control in Arabidopsis. Genes & Development 30:177-190.

 - Highlighted as an “Editor’s Choice” in the journal Science. For rRNAs, its location, location, location. Science, 22 Jan 2016: Vol. 351, Issue 6271, pp. 351.

- Recommended by Faculty 1000 (interesting hypothesis): Renate Schmidt, F1000, 2016: DOI: 10.3410/f.726063326.793521106.

 - Highlighted as ‘NORs as units of rRNA gene regulation’ in: McStay B. (2016).Nucleolar organizer regions: genomic ‘dark matter’ requiring illumination. Genes & Development 30:1598-1610.

7. Gireesha Mohannath* and Craig S. Pikaard. (2016). Analysis of rRNA Gene Methylation in Arabidopsis thaliana by CHEF-conventional 2D Gel Electrophoresis. Methods in molecular biology (Clifton, NJ) 1455: 183-202.

 (* Corresponding author)

2. Epigenetic and epigenomic approaches to improve crop plants:

For this topic, we are mainly working on rice (Oryza sativa) and tomato (Solanum lycopersicum)

Funding

DST-SERB, Government of India,

DBT, Government of India

BITS-Pilani, Hyderabad campus

Relevant publications: (GM as corresponding author):

1. Gargi Prasad Saradadevi#, Debajit Das#, Satendra K. Mangrauthia#, Sridev Mohapatra#, Channakeshavaiah Chikkaputtaiah#, Manish Roorkiwal#, Manish Solanki, Raman Meenakshi Sundaram, C.N.Neeraja, Akshay S. Sakhare, Suneetha Kota*, Rajeev K Varshney,*, and Gireesha Mohannath*. (2021). Genetic, epigenetic, and genomic approaches to enhance salt tolerance of plants. Biology 10, 1255

(* Corresponding author; # equal contribution)

 - The article has been selected as one of the excellent articles published in Biology during November-December 2021

- The article has been published as part of the Special Issue 'Crop Improvement Now and Beyond'.

3. Molecular breeding and genomic approaches to improve rice yield under low nitrogen conditions

For this topic, we are mainly working on rice (Oryza sativa). If successful, the findings can be extended to other cereals/millets that are evolutionarily more related to rice plants.

Funding

ICAR-NASF, Government of India

BITS-Pilani, Hyderabad campus

4. Regulation of rRNA genes in Oral/head and neck cancer.

Funding agencies:

BITS-Pilani, Hyderabad campus

Relevant publications:

1. Neha Priyadarshini^#, Navinchandra Venkatarama Puppala^#, Jayasree Peroth Jayaprakash, Piyush Khandelia, Vivek Sharma, and Gireesha Mohannath*. (2023). Downregulation of ribosomal RNA (rRNA) genes in human head and neck squamous cell carcinoma (HNSCC) cells is linked to rDNA promoter hypermethylation. Gene. Sep 9:147793. doi: 10.1016/j.gene.2023.147793.

(* Corresponding author; # equal contribution)

5. Antiviral defense and cellular stress response in plants

For this topic, we mainly work on Arabidopsis thaliana and Nicotiana benthamiana as model systems.

Funding agencies:

BITS-Pilani, Hyderabad campus

Relevant publications (GM as first or coauthor):

1. Aaron N. Bruns*, Sizhun Li*, Gireesha Mohannath and David M. Bisaro. (2019). Phosphorylation of Arabidopsis eIF4E and eIFiso4E by SnRK1 Inhibits Translation. FEBS Journal. 286(19): 3778-3796.

(*Equal contribution)

- Highlighted as the Editor’s choice (2019) FEBS Journal. 286 (19).

 - Highlighted in the commentary article: Miller and Dinesh-Kumar. 'A new mechanism for translational control in plants'. (2019) FEBS Journal. 286(19): 3775-3777.

2. Gireesha Mohannath, Jamie Wolf, Hui Wang, Cody Buchman, Veena Patil, Youn Lee, Allie Varner and David M. Bisaro. (2014). A complex containing SNF1-related kinase (SnRK1) and adenosine kinase (ADK) in Arabidopsis. PLoS One. 9(1):e87592.

3. Cody Buchmann, Shaheen Asad, Jamie N. Wolf, Gireesha Mohannath, and David M. Bisaro. (2009). Geminivirus AL2 and L2 proteins suppress transcriptional gene silencing and cause genome-wide reductions in cytosine methylation. Journal of Virology. 83(10): 5005-5013. 

- Highlighted by the Editors of Journal of Virology in the ‘Spotlight’ section of the journal: Geminivirus Proteins Suppress Transcriptional Gene Silencing and Methylation. (2009). Journal of Virology  p.4717.

6. To Explore multiple molecular biology tools for basic and translational research

 Various molecular biology tools being explored for different purposes:

Tool: TRBO, an engineered Tobacco Mosaic Virus-based breakthrough technology vector system to highly overexpress proteins (in transient manner) of interest using a rapid and low-cost plant system.

Purpose:

i. To enhance genome editing efficiency

ii. To overexpress/oral feeding of proteins of therapeutic interest

iii. To overexpress proteins for purification and analysis (enzyme analysis, proteomics, etc)

Tool: M1GS an engineered bacterial ribozyme, as a RNA-cleaving/reverse-genetic tool

Purpose:

i. To develop as a novel anti-cancer modality by downregulation of rRNA genes in cancer cells

ii. To establish this tool as a reverse-genetic tool in plants

Tool: Inhibitors of epigenetic modifiers

Purpose:

i. To improve genome-editing efficiency

ii. To improve rates of mutagenesis

Tool: RNA mimics of GFP

Purpose:

i. To develop a new virus (RNA)-detecting tool

ii. To establish this system in plants

Funding agencies:

ICMR, Government of India

DBT, Government of India

BITS-Pilani, Hyderabad campus

Relevant publications (GM as corresponding or coauthor)

1. Shifa Bushra Kotwal#, Nidhi Orekondey#, Gargi Prasad Saradadevi#, Neha Priyadarshini#, Navinchandra V. Puppala#, Mahak Bhushan, Snehasri Motamarry, Rahul Kumar, Gireesha Mohannath* & Ruchi Jain Dey*. (2023). Multidimensional futuristic approaches to address the pandemics beyond the COVID-19. Heliyon (Cell Press) 9 e17148.

(*Corresponding authors; # equal contribution)

2. Navinchandra Puppala, Purnima D*, Gireesha Mohannath. (2022). Recent advances in the use of Nanocellulose and Nanolignin in the delivery of biological and non-biological  rugs: A review. Cellulose  30: 1334-1354. https://doi.org/10.1007/s10570-022-04977-w

(* Corresponding author)