TITLE:
Impact of Essential Micronutrient, Zn, on Growth and Chlorophyll Biosynthesis in Young Zea mays Seedlings
AUTHORS:
R. (Chinchalkar) Waghmare, R. Gadre
KEYWORDS:
Amino Levulinic Acid, Amino Levulinic Acid Dehydratase, Chlorophyll Biosynthesis, Growth Effects, Maize, Zn Effects
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.9 No.9,
August
21,
2018
ABSTRACT: The
present study analyses growth and chlorophyll biosynthesis in young maize
seedlings in response to Zn supply over a wide range of concentrations. Supply
of 0 - 5 mM
ZnCl2 to 3 days old light grown maize seedlings led to gradually
increased accumulation of Zn in the shoot tissue, while in the root tissue
substantial increase was observed at/and above 0.1 mM ZnCl2. Zn
supply significantly reduced the overall growth of maize seedlings mostly at 1 - 5 mM
ZnCl2 exerting strong correlation and the observed effect was more
substantial for root tissue. Amongst the biochemical parameters, increase in
protein and proline content was more prominent in root tissue than the shoot,
while RNA content was reduced in shoot tissue. Zn treatment to light grown
seedlings significantly increased the chlorophyll, carotenoid content, while in
dark grown seedlings it had marginal/no effect. Delta amino levulinic acid
(ALA) content in both the regimes was increased at higher Zn concentrations.
Also ALA synthesis was increased in both the regimes, but non significantly. Zn
enhanced ALA dehydratase (ALAD) activity of light as well as dark grown
seedlings being significant in former. The results demonstrate that the Zn
accumulation and growth effect at higher Zn concentrations in maize depend upon the tissue with root as the target site and
shoot growth are mainly
influenced by ALA and subsequently ALAD in maize seedlings.