Saminathan, T., Alvarado, A.,
Lopez, C., Shinde, S., Gajanayake, B.,
Abburi, V.L., Vajja, V.G.,
Jagadeeswaran, G., Reddy, K.R.,
Nimmakayala, P. and Reddy, U.K.
2019
"Elevated carbon dioxide and drought
modulate physiology and storage-root
development in sweet potato
by regulating microRNAs."
Functional & Integrative Genomics
19: 171-190.
SUMMARY:
Drought has
a substantial
negative impact
on photosynthesis,
chlorophyll and biomass
of sweet potato plants.
Elevated CO2
improved these
and other
growth-related
parameters.
In the combined
elevated CO2 and
drought treatment,
the positive effects
of elevated CO2
more than
sufficiently offset
the negative effects
of drought.
Saminathan et al. say
"the decrease in photosynthesis
under drought stress was mitigated
by elevated CO2"
and that
"the significant reduction in biomass
when plants were grown under drought
was completely reversed
under elevated CO2."
They report that such responses
were also found when
biomass was apportioned
into leaf, stem and root sinks.
The authors conclude that
"elevated CO2
ameliorated
the adverse effects
of drought stress"
on sweet potato.
Great news for
this key global
food crop.
DETAILS:
Saminathan et al. (2019) say
sweet potato (Ipomoea batatas)
is the seventh most-produced
food crop worldwide and
is a source of starch, ethanol,
animal feed and other
industrial products.
The team of eleven researchers
designed and conducted
an experiment to investigate
the interactive effects of
elevated CO2 and drought
on the growth of sweet potatoes.
They grew plants of the variety
Beauregard (B14) in a sunlit
Soil-Plant-Atmosphere-Research (SPAR)
facility under controlled environment
conditions at the Rodney Foil Plant
Science Research Center of
Mississippi State University,
Mississippi, USA.
Sweet potato slips were transplanted
into the SPAR chambers and
exposed to one of two atmospheric
CO2 concentrations, control (380 ppm)
or elevated (760 ppm).
Initially, all plants were grown
under 100% field capacity
water conditions.
Then, at 41 days after transplanting
(DAT), Saminathan et al. subjected
half of the plants in each CO2 treatment
to drought (40% water field capacity)
until the experiment ended at 97 DAT.
