| The response of maize (Zea mays L.) roots to oxygen deprivation involves an altered gene expression and protein synthesis. Maize cytosolic glyceraldehyde-3-phosphate dehydrogenase (GAPDH) has been identified as one of the anaerobic polypeptides and mRNAs corresponding to a member of the gpc multi-gene family, gpc3, increase under anaerobiosis. This study extends further analysis of the gpc gene family, with specific emphasis on gpc4. Analysis of full length cDNA clones for GAPC2, GAPC3 and GAPC4 revealed that the deduced amino acid sequence of GAPC4 has 99.4% identity with the GAPC3 cDNA clone as compared to only 81% with either GAPC1 or GAPC2. Northern blot analysis revealed a maximum transcript accumulation 24 h after anaerobiosis and anoxic specific induced expression for gpc3 and gpc4.The organization of genomic clones of gpc2 and gpc4 is complex in nature with 10 and 11 introns in their coding regions, respectively. The positions of introns are conserved in both gpc2 and gpc4, except for the Transient expression analysis of GUS activity driven by the gpc4 promoter in maize cell suspension cultures showed an induced expression of approximately three fold over aerobic control, during anaerobiosis. |
