Screening Arabidopsis Activation Tagged Lines Based on Tolerance to Low Zn in Hydroponics
Zinc (Zn) is an essential nutrient for all living organisms. Understanding how plants respond to low Zn is important, as Zn deficiency is a major contributing factor in reducing crop yield and productivity throughout the world. Zn efficiency (ZE) is the ability of plants to maintain high yield under low-Zn conditions. The objective of this study was to conduct a large-scale screening of 30,000 T-DNA activation tagged Arabidopsis lines to identify mutants with superior ZE. Our hypothesis was that overexpression of certain genes will lead to ZE in Arabidopsis. We have established a hydroponic screening system and isolated a number of putative Arabidopsis mutants, which we are currently screening for confirmation. The hydroponic solution contained 1 mM KNO3, 1mM Ca(NO3) 2, 0.05 mM NH4H2PO4, 0.25 mM MgSO4, 0.1 mM NH4NO3, 50 uM KCl, 12.5 uM H3BO3, 0.1 uM H2MoO4, 0.1 uM NiSO4, 0.4 uM MnSO4, 1.6 uM CuSO4, 96uM Fe(NO3) 3-H3HEDTA, 0.1 pM ZnSO4-H3HEDTA and 2 mM MES at pH 6.0. Zn-efficient Arabidopsis mutants were recovered and moved to agar plates with full nutrients for three days and then to soil. After growing the mutants in soil until flowering and seed set, T3 seeds were harvested for secondary screening. Thus our hydroponic screening appears to be a reliable and manageable method to screen Arabidopsis for ZE. However, the mutants identified in this study need to be validated in secondary screening.