Transformation of Soy (Glycine max) for Heightened Expression of the SIZ1 Gene

Abstract

SIZ1 is a member of the PIAS family of proteins. One of this enzyme’s functions is to act as an E3 ligase, conjugating small ubiquitin-related modifiers (SUMOs) to various substrate proteins as part of the process called sumoylation (Cheong et al., 2009). Sumoylation alters the chemical conformation and function of substrate proteins, affecting their interactions with other cellular constituents and their resultant physiological roles. At the molecular level, sumoylation affects myriad biochemical processes, ranging from DNA repair and regulation of the cell cycle to signal transduction, nuclear transport, and modulation of transcription factor activity. Constitutive overexpression of the SIZ1 gene in transgenic creeping bentgrass (Agrostis stolonifera L.) has been demonstrated to result in more robust growth and higher levels of photosynthetic activity than are seen in non-transformed controls; heightened SIZ1 expression also results in increased levels of adaptive response to stressors including elevated ambient temperatures, drought conditions, and phosphate deprivation (Li et al., 2012). With the current experiment, Agrobacterium tumefaciens is being utilized to transform soy (Glycine max) with an additional copy of the endogenous SIZ1 gene; the aim is to develop improved soy cultivars whose elevated expression of SIZ1 will result in increased resilience under such stress conditions as are increasingly experienced during the cultivation of this economically important plant.