Application of a 2-dimensional phenotyping platform to screen Bangladeshi rice accessions (Oryzasativa) for salinity stress tolerance
Salt stress due to excess sodium chloride (NaCl) accumulation in agricultural soils degrades arable land worldwide, consuming 2,000 hectares daily. Rice (Oryza sativa) is responsible for feeding over half of the world’s population and is one of the most salt sensitive cereal crops. High concentrations of NaCl in the soil affect plants in two ways, including osmotic stress in the root zone, followed by salt toxicity when sodium enters the plant root and is translocated in the xylem to the shoot. Sodium competes with potassium for transport and inclusion into several important plant processes, leading to reduced plant health and yield. A previously established salinity screening protocol was used to phenotype a rice diversity panel from Bangladesh for salinity tolerance. The first 42 of 234 rice accessions collected in Bangladesh were grown for 11 days in hydroponic solution, with a salt treatment consisting of plant exposure to 53mM NaCl in the nutrient solution for a total of 7 days. Roots were digitally imaged on the first treatment day, day 4, and then again on day 7. These root images were processed using novel RootReader2D software, and relative root growth (RRG = treatment root growth rate/control root growth rate) was calculated from these data to quantify salt tolerance. Initial results showed that the rice lines exhibited a wide range of salt tolerance within this subset of the panel, ranging from a RRG of 1.00 (no inhibition) to as low as 0.40 (60% inhibition). These results provide insight into the diversity available in landrace varieties of rice and how they can be used to improve our understanding of the responses rice may use to deal with salt stress.
After spending my second summer at the Boyce-Thompson Institute, I was able to see the results of last summer carry over and aid in my current project. In addition to learning new laboratory techniques I was able to take skills that I had previously learned and refine them to increase their efficiency and thus the quality of my work. I felt much more confident using equipment, helping to design and carry out my experiment, as well as speaking to others and explaining my project and its significance. This summer I was also able to see more of a direct application of my work and how it may be able directly help those who are farming in areas with saline soils. Additionally, this internship has showed me that I’m very drawn to scientific work and that I would like to pursue a career in science and/or science communication.