ARS | Publication request: Expression analysis of metal-related genes in flag leaves of rice

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: December 2, 2006
Publication Date: January 13, 2007
Citation: Narayanan, N.N., Seman, Z.A., Vasconcelos, M.W., Grusak, M.A. 2007. Expression analysis of metal-related genes in flag leaves of rice [abstract]. In: Plant & Animal Genomes XV Conference, January 13-17, 2007, San Diego, California. Poster P828.

Technical Abstract: Rice is an important food crop, but it is a poor source of essential micronutrients such as iron and zinc. In order to improve the metal concentration of rice grains, more information is needed on the molecular players that help mobilize metals from leaves to developing seeds. To profile several genes simultaneously, a cDNA macroarray was developed using 36 metal-related genes from rice, including ZIPs, NRAMPs, and YSLs (coding for known or potential metal transporters), as well as NAS, FER, FRO, NAAT, FDH, GSTU, and PDR (involved in metal homeostasis). Because flag leaves are the major source of phloem-delivered photoassimilates and mineral nutrients for developing seeds, we analyzed the expression of these metal-related genes in flag leaves and compared them to non-flag leaves of four different rice cultivars (Cocodrie, Taipei 309, IR58, and IR68144) during the period of mid-grain fill. These four cultivars differ in their seed iron and zinc concentrations. Twenty-four of 36 genes exhibited low to non-detectable signals in the macroarray, while 12 genes were found to be highly expressed in flag leaves; few differences were found between flag and non-flag leaves. Gene expression profiles will be presented for these cultivars, along with quantitative PCR results for metal gene expression in flag leaves of an additional 61 rice accessions that were selected for their phenotypic diversity. Expression results will be analyzed with respect to seed mineral concentrations.