Interactions of C4 subtype metabolic activities and transport in maize are revealed through the characterization of dct2 mutants. Zea mays

We sequenced mRNA from from four segments along a developing 9 day old third maize leaf of WT W22 accession and ZmDCT2 KO (in W22 background - dct2-1::Ac) plants, to identify changes in gene expression in dct2-1::Ac as a response to the loss of ZmDCT2 function. Overall design: The segments were referenced relative to the position of the ligule of leaf 2 as this point represents the source-sink boundary in a wild-type leaf and the transition from shaded leaf tissue to fully light exposed. Segment -4 was isolated at the base of the leaf blade that is photosynthetically inactive, -1, defined as the sink to source transition zone (just below the point of leaf emergence from the whorl), segment +4, from a fully light exposed and photosynthetically active region in the mid-leaf (maturation zone), and +10, the tip of the leaf and the terminally differentiated tissue