Journal of Plant Pathology & Microbiology

Impact of anatomical traits of maize (Zea mays L.) leaf as affected by nitrogen supply and leaf age on bundle sheath conductance

International Conference on Plant Physiology & Pathology

June 09-10, 2016 Dallas, USA

Moges Retta

Catholic University of Leuven, Belgium

Posters & Accepted Abstracts: J Plant Pathol Microbiol

Abstract:

The mechanism of photosynthesis in C4 crops depends on the archetypal Kranz-anatomy. To examine how the leaf anatomy, altered by nitrogen supply and leaf age, affects the bundle sheath conductance (gbs) when maize (Zea mays L.) plants grown under three contrasting nitrogen levels. Combined gas exchange and chlorophyll fluorescence measurements were done on fully grown leaves at two leaf ages. The measured data were combined with a biochemical model of C4 photosynthesis to estimate gbs. The leaf microstructure and ultrastructure were quantified using images obtained from micro-computed tomography and microscopy. There was also a strong positive correlation between gbs and leaf nitrogen content (LNC) while old leaves had lower gbs than young leaves. Leaf thickness, cell wall thickness of bundle sheath cells and surface area of bundle sheath cells per unit leaf area (Sb) correlated with gbs although they were not significantly affected by LNC. As a result, the increase of gbs with LNC was little explained by the alteration of leaf anatomy. In contrast, the combined effect of LNC and leaf age on Sb was responsible for differences in gbs between young leaves and old leaves. Future investigations should consider changes at the level of plasmodesmata and membranes along the CO2 leakage pathway to unravel LNC and age effects further.

Biography :

Email: moges.ash@gmail.com