U.S. Department of Agriculture: Agricultural Research Service, Lincoln, Nebraska
Date of this Version
3-2017
Citation
ANNUAL REPORT OF THE BEAN IMPROVEMENT COOPERATIVE, No. 60, March 2017. Published by USDA.
Abstract
INTRODUCTION Over more than 100 years agricultural scientists all over the world have developed high yielding crop varieties to meet the energy demand of increasing population. However the nutritional qualities have not been given priorities as a result world is facing with serious malnutrition problem. Two of the most prominent deficiencies affecting the world are of iron (Fe) and zinc (Zn). Among others Fe is vital in building proteins of red blood cells, whereas Zn is essential in cellular growth and development. Epigenetic mechanisms such as DNA methylation, histone modification, and small interfering RNA (sRNA) regulate the transcription of DNA in living organisms (He et al. 2011). It has been reported that the abiotic and biotic stresses such as changes in temperature, pests, drought, disease, and the concentration of minerals and metals in the surrounding soil are involved with the changes in epigenetic and transcriptomic components (Hu et al. 2012) in plant. The long-terms goals of our work are to identify the epigenetic and transcriptomic components involved in the acquisition and translocation of micronutrients in common bean.
MATERIALS AND METHODS In our work, we applied higher concentrations of Fe to a common bean genotype G122 which was previously identified as a genotype that is highly responsive to elevated Fe and other health-related minerals (Bauduin et al. 2014). The treated and control plants were planted in 8.5”x11” pots filled with Sunshine Mix. The sunshine mix was kept soaked with water until germination. After germination we kept the clear saucers beneath the treated pot filled with a solution of Fe (200 mg-1L) until the leaves reached 50% senescence while the control plant continued to receive water. At 50% leaf senescence, the stems of the plants were harvested and chromatin and total histone were isolated using the Chromaflash Plant Chromatin Extraction Kit (P-2022) and Epiquik Total Extraction Kit (OP-0006) respectively (www.epigenetek.com). One hundred nanograms of total histone of treated and control samples were added into the wells of 20 H3 modification sites in duplication for identifying each of the 20 histone modification patterns. Following the procedure described in the EpiQuik Histone H3 Modification Multiplex Assay Kit (P-3100), the intensity of absorbance of the H3 modification sites was measured at 450 nm wavelength by a BioTek Microplate reader (Elx808). Using the formula (given below) provided by the EpiQuik Histone H3 Modification Multiplex Assay Kit, histone modifications for 20 of the 21 H3 modification sites were calculated in ng/μg of histone 3 protein and compared between treated and control stems and presented as fold change (Table. 1).
Comments
U.S. government work.