Plant Biology and Biotechnology

Crop Improvement

The Plant-microbe Interaction Group (Sonti) in New Delhi seeks to understand the mechanisms of attack and defense in the interaction between plants and their pathogens. In addition, the Group is using molecular marker/genomics assisted selection methods for improvement of rice cultivars for enhanced biotic stress tolerance. The Crop Improvement Group (Reddy) in New Delhi focuses on translational research in the area of agricultural biotechnology and crop improvement, using transgenic and targeted genome-editing technology in the indica rice cultivar to improve rice plant architecture for enhanced productivity. The intention is to simultaneously engineer resistance to multiple herbicides as well as biotic stresses with different modes of action to control weeds, and to promote the cultivation of direct-seeded rice (DSR). In addition, engineering via genome editing is pursued in order to improve the nutritional quality of rice. The Nutritional Improvement Group (Kaul) in New Delhi continues to use the latest genetic engineering technologies to improve traits and the nutritional value of cereals, legumes and tomatoes. The Bacteriology Group in Trieste (Venturi) focuses on bacterial interspecies signaling in plant-associated microbiomes and the identification and development of plant bacterial probiotics. The newly formed Plant Systems Biology Group (Donaldson) in Cape Town is studying salinity stress adaptation using Arabidopsis as a model as well as economically important crops, such as maize and sorghum. In addition, it is initiating studies on the role of the microbiome in biotic stress tolerance in sorghum.

Highlights

The Crop Improvement Group in New Delhi has generated many useful CRISPR-edited rice mutants with improved traits, including grain yield, droughttolerance, and nutritional quality, with the goal of pyramiding the mutants to create a superior rice variety. The improved high-yielding rice mutants are at an advanced stage, and ICGEB signed an MOU with IARI, New Delhi, to carry out All-India Coordinated Rice Improvement Programme (AICRIP) fi eld trials for commercialization and release. Further, the group identifi ed that potassium phosphite acts as a defensive elicitor and excellent fungicide to protect against blast disease in ptxD transgenic rice (Mehta et al, Pestic Biochem Physiol, 2022). In addition, transgenic rice expressing the detoxifying gene igrA showed modest tolerance to glyphosate (Panditi et al, Plant Cell, Tissue Organ Cult. 2022). The Plant Systems Biology Group in ICGEB Cape Town performed studies on saline tolerance, using model Arabidopsis as well as the commercial cereal sorghum. One study was published, correlating auxin levels to salt stress growth conditions (Cackett et al., Front Plant Sci, 2022). In addition, microbiome studies have been initiated in sorghum and rice, comparing microbial communities from several geographical areas, in different plant compartments and growth conditions.

The Plant Transcription Regulation Group in New Delhi continues its work on the Mediator (MED) multiprotein complex that plays central role in the regulation of eukaryotic transcription. Earlier studies had deduced the structural topology of the MED complex in Arabidopsis. In that study, two subunits, MED14 and MED17, were identified as being very important for the structural integrity of the complex (Maji et al., Nucleic Acids Res 2019). Current focus is on these two subunits, to understand the physiological function of MED in Arabidopsis. Studies have identifi ed the previously unexplored role of jasmonate (JA) signaling components and Mediator complex and their integration with auxin signaling during thermomorphogenesis. Thermomorphogenesis is a collective term for warm temperature-induced morphological changes in plants. It was found that warm temperature promotes accumulation of the JA-signalling receptor CORONATINE INSENSITIVE 1 (COI1) degradation of JA-signalling repressor JASMONATE-ZIM-DOMAIN PROTEIN JAZ9), which lead to the de-repression of MYC2 and enable it to activate the expression of MED17. MED17 then occupies the promoters of thermosensory genes to induce their expression. Moreover, MED17 also facilitates enrichment of H3K4me3 on the promoters of these genes. Overall, this study elucidates the role of Mediator complex as an integrator of JA and auxin signaling pathways during thermomorphogenesis. This work has been published in Plant Physiology (Agrawal et al., 2022).

The Bacteriology Group in ICGEB Trieste continues studies on plant microbiomes and published an article in collaboration with the Computational Biology Group and research groups in Colombia, Ethiopia, Burundi and Vietnam, on the rhizosphere microbiome of the coffee plant. Results showed common core groups of bacteria amongst all the microbiomes, indicating potential bacteria that can be isolated and used as plant probiotics (Bez-Esposito et al., Rhizosphere, 2022). The Group was also involved in collaborative papers with research groups in Namibia, Belgium and Italy on topics of plant-beneficial bacteria and sustainable agriculture. Finally, it performed studies in a topic of long-standing interest to the Group: cell-cell communication in bacteria, involving interspecies signaling (Bez et al., mSystems 2023). 

The Nutritional Improvement of Crops Group in ICGEB New Delhi continued to examine the biofortification of rice, by studying, through a combination of computational, genome editing and other molecular approaches, the function of ZRT/IRT transporter-like proteins and the role they play in zinc uptake and transport (Mohammed er al., J Biomol Struc Dyn 2022). Other studies included the molecular mechanisms in maize underlying the acquisition, transportation and utilization of Pi, which may lead to engineering genotypes with highly efficient phosphorus use. A study was performed on the comparative transcriptional expression profiling of 12 selected P-responsive genes in the Pi stress-tolerant maize inbred line HKI-163, under sufficient and deficient Pi conditions (Yadava et al., Physiol Mol Biol Plants 2022).