Functional and Physiological Mechanisms That Mediate Aluminum Tolerance in Sorghum

Aluminum (Al) is the third richest element in the Earth’s crust. In highly acidic soils with pH values below 5.0, Al is solubilized as the highly phytotoxic Al3+ species, which inhibits root growth and damages root systems. An important physiological mechanism in Al tolerance involves the exudation of organic acids (OA), such as malate and citrate from their root apexes. In sorghum, Al-activated root citrate exudation has been identified as a major physiological mechanism for Al tolerance. This function is controlled by an Al tolerance gene in Sorghum, called SbMATE, by trans-acting components of a gene. Recently, small RNAs (sRNA) have been identified as another potential regulatory mechanism for gene expression. My project involved testing if SbMATE gene expression is regulated in part by small RNAs. We made sRNA libraries from a sorghum Al-sensitive line, a sorghum Al-tolerant line and a hybrid line derived from these two parental lines. Each sample contained two separate treatments (with or without Al) for each of the three lines, making a total of six samples. We wanted to identify sRNAs that display differential expression patterns between the Al-sensitive line, the Al-tolerant line and their hybrid line. Those candidate sRNAs will be subjected to further examinations for their roles in regulation of the SbMATE gene expression.

My Experience

As an intern I really enjoyed my summer research project, because it incorporated all of my favorite biology sub-fields (biochemistry, molecular biology and genetics). I thoroughly appreciated how helpful my mentor was in guiding me through my research project. I even got to work with other scientist in my labs. I gained novel experience in what it may take to be a scientist and the responsibilities that I might endure as a graduate student. This experience has reiterated my plans for graduate school and what projects I would like to conduct.