TITLE:
Effect of Various Intensities of Drought Stress on δ13C Variation among Plant Organs in Rice: Comparison of Two Cultivars
AUTHORS:
Mana Kano-Nakata, Jiro Tatsumi, Yoshiaki Inukai, Shuichi Asanuma, Akira Yamauchi
KEYWORDS:
δ13C, Drought, Plant Parts, Rice
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.5 No.11,
May
21,
2014
ABSTRACT: The δ13C value is
widely used to assess the effects of drought on water status in plants.
However, there is little information regarding the δ13C signature in
different organs of rice. We conducted a field study to examine whether the δ13C
among different plant parts would be affected by the intensities of drought,
and to evaluate genotypic variation in δ13C fluctuation among plant
parts affected by drought intensities. Two cultivars, “Nipponbare” (Oryzasativa ssp. japonica) and “Kasalath” (O. sativa ssp. indica), were grown in the field
with a line-source sprinkler system. The δ13C values of panicles,
flag leaves, straws, culms, and roots were measured from plant samples. The δ13C
value increased as drought stress increased, especially in the panicles and roots.
“Nipponbare” showed higher values of δ13C than “Kasalath” under the
well-watered and mild drought stress conditions, but there was no significant
difference between the genotypes in the δ13C value under the severe
drought stress condition. The variation in δ13C value among
different plant parts was also increased with increasing drought stress. In
contrast, these variations were small under well-watered conditions. Furthermore,
there was much greater variation in the δ13C value among different plant
parts in “Kasalath” than in “Nipponbare” when the plants were grown under
drought stress conditions. A significant negative relationship was observed
between the δ13C value of panicles and shoot dry matter production,
suggesting that the δ13C value of panicles may be the best indicator
of plant water status in rice.