Research Experience

Engineering stomata to improve Soybean leaf and whole-plant water use efficiency and performance under droughts

As water will be a critical resource limiting global crop growth and yield, developing crops that use water efficiently is essential to maintain our food supply. At the heart of addressing this need lie stomata (microscopic pores present on the leaf surface) that determine plant-atmosphere CO2-water exchange and hence photosynthesis, growth, and water use. My current work at UIUC aims to assess if reduced stomatal density can help us improve the leaf water-use efficiency (or ratio of photosynthesis to transpiration) in legumes and whether this improvement at the leaf level translates into improved plant water-use efficiency and performance under droughts. I use a variety of approaches including molecular tools, gas exchange, imaging coupled to artificial intelligence, and phenomics to study CO2-uptake and water-use at multiple scales.

Leaf anatomical and biochemical determinants of mesophyll conductance in C4 and C3 grasses

Increasing mesophyll conductance (or the diffusion of CO2 from intercellular air spaces to the first site of carboxylation) has been proposed as a major strategy to increase photosynthesis and water-use efficiency. However, unlike C3 species, there is very limited understanding of mesophyll conductance in C4 species- a group of plants that includes our major ecologically and agriculturally important species. Using real-time stable isotope discrimination techniques coupled to advanced microscopy, my research has improved our understanding of C4 mesophyll conductance and its variability and identified several target leaf anatomical properties that can be manipulated to improve mesophyll conductance. I also demonstrated that manipulation of the identified leaf property, that is cell wall composition and thickness, helps improve mesophyll conductance and hence photosynthesis, growth and water-use efficiency in rice and Sorghum.

Ecophysiological responses of Australian grasses to climate change (elevated CO2 x droughts)
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As CO2 is a raw material for photosynthesis, plants are expected to absorb extra CO2 as biomass and thus help mitigate rising CO2. However, this expectation is seldom met as several abiotic and biotic factors influence the capacity of plants to absorb and sequester CO2. Leveraging the unique Eucalyptus Free Air CO2 Enrichment Experiment, my work tested how water and soil phosphorus availability affect the photosynthesis and growth responses of diverse Australian woodland grasses to elevated CO2.

Among many findings, I demonstrated that elevated CO2 did stimulate photosynthetic CO2 uptake, however, it did not lead to growth enhancement or CO2 sequestration. In follow-up collaborative research we demonstrated that the majority of CO2 absorbed through enhanced photosynthesis was released back to the atmosphere through enhanced respiratory processes and soil microbial competition for P.

Mycorrhizal colonization and arsenic stress in crops

Arsenic (As) is a ubiquitously present carcinogenic metalloid whose contamination is widespread in several parts of the world including several states of India. Unfortunately, these arsenic-contaminated areas are also major zones for the cultivation rice- a critical food crop.  As a research fellow at Bhabha Atomic Research Center, my work focused on assessing how mycorrhizal colonization and altered nutrient concentrations impact arsenic accumulation and key physiological and growth parameters in rice varieties.