Ej. Robertson et Rm. Leech, SIGNIFICANT CHANGES IN CELL AND CHLOROPLAST DEVELOPMENT IN YOUNG WHEAT LEAVES (TRITICUM-AESTIVUM CV HEREWARD) GROWN IN ELEVATED CO2, Plant physiology, 107(1), 1995, pp. 63-71
Cell and chloroplast development were characterized in young Triticum
aestivum cv Hereward leaves grown at ambient (350 mu L L(-1)) or at el
evated (650 mu L L(-1)) CO2. In elevated CO2, cell and chloroplast exp
ansion was accelerated by 10 and 25%, respectively, in the first leaf
of 7-d-old wheat plants without disruption to the leaf developmental p
attern. Elevated CO2 did not affect the number of chloroplasts in rela
tion to mesophyll cell size or the linear relationship between chlorop
last number or size and mesophyll cell size. No major changes in leaf
anatomy or in chloroplast ultrastructure were detected as a result of
growth in elevated CO2, but there was a marked reduction in starch acc
umulation. In leaf sections fluorescently tagged antisera were used to
visualize and quantitate the amount of cytochrome f, the alpha- and b
eta-subunits of the coupling factor 1 in ATP synthase, D1 protein of t
he photosystem II reaction center, the 33-kD protein of the extrinsic
oxygen-evolving complex, subunit II of photosystem I, and ribulose-1,5
-bisphosphate carboxylase/oxygenase. A significant finding was that in
10 to 20% of the mesophyll cells grown in elevated CO2 the 33-kD prot
ein of the extrinsic oxygen-evolving complex of photosystem II and cyt
ochrome f were deficient by 75%, but the other proteins accumulated no
rmally.