Development and Evaluation of Ds Tagged Mutants in Sorghum
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Date
2013
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UAS, Dharwad
Abstract
Maize Dissociator (Ds)-mediated insertional inactivation tagging and activation
tagging were attempted in M 35-1, a popular rabi variety of Sorghum bicolor L. (Moench)
for its gene discovery and functional genomics. Six and five transgenic events produced
from pUR224NA and pNU435, respectively were used as the Ds starter lines for insertional
inactivation tagging. Five Ds events obtained with pUbiDs were used for activation tagging.
Five events of iAc plants obtained with pKU352NA were used as the source of transposase.
Ds starter lines with single copy of the launch pad (T-DNA/Ds) were selected by
segregation analysis and used for crossing with iAc plants following artificial emasculation
and hand pollination. The seeds set on the female plant were harvested and sown in the
green house. The plants showing the presence of both Ds and iAc as tested by various PCR
were regarded as true F1s. The seeds borne on the true F1s were harvested to raise the F2
generation.
Among the F2 plants, those with transposed Ds (excised out of launch pad and reinserted
within the genome) and without iAc were identified by various PCR as Ds tagged
stable mutants. In total, five and three insertionally inactivated mutants (IIM) were obtained
from the launch pads of pUR224NA and pNU435, respectively. In addition, three activation
tagged mutants (ATM) were recovered from the launch pad of pUbiDs. Majority of the
mutants showed unlinked Ds transposition as they did not carry the empty launch pad (TDNA
without Ds). Six mutants (IIM2, IIM3, IIM6, IIM7, ATM1 and ATM3) with unlinked
transposition showed Ds insertion within genic regions, indicating tagging of six different
genes of sorghum. Preliminary phenotyping of the Ds tagged mutants (without ascertaining
their zygosity) under green house for various morphological traits did not reveal any gross
morphological changes when compared to M 35-1 (wild type).