Abstract Lipoxygenase (LOX) is a common enzyme
which catalyzes lipid peroxidation of seeds and conse-
quently enhances seed quality deterioration and decreases
seed viability. During seed storage, peroxidation of unsat-
urated fatty acids occur due to enhancement of LOX
activity which directly leads to reduction in seed vigour
and deterioration of grain nutritional quality. This study
was undertaken to overcome these problem during rice
seed storage by attenuating LOX activity using RNAi
technology. To improve seed storage stability, we down
regulated LOX gene activity by using a functional fragment
of the LOX gene under the control of both constitutive
(CaMV35S) and aleurone-specific (Oleosin-18) promoter
separately. To understand the storage stability, RNAi–LOX
seeds and non-transgenic control seeds were subjected to
accelerated aging at 45 C and 85 % relative humidity for
14 days. Our studies demonstrate that down regulation of
LOX activity reduces the seed quality deterioration under
storage condition. In addition GC–MS analysis revealed
that reduction of fatty acid level in non-transgenic seeds
during storage was higher when compared with that of
transgenic rice seeds. Furthermore, the transgenic rice
seeds with reduced LOX activity exhibited enhanced seed
germination efficiency after storage than that of non-
transgenic rice seeds. This study will have direct impact on
nutritional stability of quality rice grains.
Keywords Accelerated aging Lipid peroxidation
Lipoxygenase RNAi Seed deterioration Transgenic rice
Abbreviations
LOX Lipoxygenase
MDA Malondialdehyde
HNE Hydroxynonenal
FFA Free fatty acid
ROS Reactive oxygen species
HPOD Hydroperoxyoctadecadienoic acid
AA Accelerated aging
RH Relative humidity
EC Electric conductance
AAS Atomic absorption spectroscopy