31 research outputs found
Cosmoglobe: Towards end-to-end CMB cosmological parameter estimation without likelihood approximations
We implement support for a cosmological parameter estimation algorithm as
proposed by Racine et al. (2016) in Commander, and quantify its computational
efficiency and cost. For a semi-realistic simulation similar to Planck LFI 70
GHz, we find that the computational cost of producing one single sample is
about 60 CPU-hours and that the typical Markov chain correlation length is
100 samples. The net effective cost per independent sample is 6 000
CPU-hours, in comparison with all low-level processing costs of 812 CPU-hours
for Planck LFI and WMAP in Cosmoglobe Data Release 1. Thus, although
technically possible to run already in its current state, future work should
aim to reduce the effective cost per independent sample by at least one order
of magnitude to avoid excessive runtimes, for instance through multi-grid
preconditioners and/or derivative-based Markov chain sampling schemes. This
work demonstrates the computational feasibility of true Bayesian cosmological
parameter estimation with end-to-end error propagation for high-precision CMB
experiments without likelihood approximations, but it also highlights the need
for additional optimizations before it is ready for full production-level
analysis.Comment: 10 pages, 8 figures. Submitted to A&
Decoding allelic diversity, transcript variants and transcriptional complexity of CENH3 gene in Brassica oleracea var. botrytis
<span style="font-size:11.0pt;font-family: "Times New Roman";mso-fareast-font-family:"Times New Roman";mso-bidi-font-family: Mangal;mso-ansi-language:EN-GB;mso-fareast-language:EN-US;mso-bidi-language: HI" lang="EN-GB">Assessment of <i style="mso-bidi-font-style:normal">Arabidopsis thaliana <span style="mso-bidi-font-style:italic">CENH3</span></i> promoter in <i style="mso-bidi-font-style:normal">Brassica juncea</i> for development of haploid inducer lines</span>
425-430<span style="font-size:11.0pt;font-family:
" times="" new="" roman";mso-fareast-font-family:"times="" roman";mso-bidi-font-family:="" mangal;mso-ansi-language:en-gb;mso-fareast-language:en-us;mso-bidi-language:="" hi;mso-bidi-font-weight:bold"="" lang="EN-GB">Centromeres are epigenetically specified by the centromeric histone H3 protein (CENH3). The
timing and level of expression of CENH3 is tightly regulated to match the
demands of the host cell. So far in plants, only CENH3 promoter of Arabidopsis thaliana (L.) Heynh. has
been characterized. However, whether CENH3 promoters retain their
characteristic mode of regulation in other species remains to be established.
In the present study, activity of AtCENH3
promoter was investigated using reporter gene assay in <i style="mso-bidi-font-style:
normal">Brassica juncea (L.) Czern. A 1156 bp promoter fragment of AtCENH3 gene (<i style="mso-bidi-font-style:
normal">At1g01370) including the first 111 nucleotides of the coding
sequence was amplified and cloned into the pORE-R2 binary vector to ensure translation
fusion with the uidA coding
sequences. The Agrobacterium tumefaciens
strain GV3101 harbouring the recombinant construct was used to transform B. juncea cv. RLM198 hypocotyl explants.
Histochemical assay of T0 and T1 transgenics showed GUS
expression in shoot apical meristem, leaf, sepal, flower pedicel and root tip.
Intense GUS expression was observed in meristematic tissues, particularly at
shoot and root apices. However, mature leaves, flowers, pollen and ovules
exhibited very low or no GUS expression. Our results showed that AtCENH3 promoter regulates cognate gene
expression in Brassica juncea as it
does in A. thaliana, and hence a
suitable candidate for developing haploid inducer line in <i style="mso-bidi-font-style:
normal">B. juncea. </span
Magneto-priming promotes nitric oxide via nitric oxide synthase to ameliorate the UV-B stress during germination of soybean seedlings
Cloning, characterization and expression analysis of <em>APETALA2</em> genes of <em>Brassica juncea</em> (L.) Czern.
604-610The APETALA2/Ethylene-Responsive Factor (AP2/ERF) is one of the largest gene families encoding several plant specific transcription factors. It plays significant roles in growth and development process, biotic and abiotic stresses, and responses to hormones. AP2 is a homeotic gene governing floral meristem specification, floral organ determination and floral homeotic gene expression in Arabidopsis. The basic structure of AP2 gene was unchanged during evolution in diploid species. The present study was undertaken to find whether AP2 has undergone any change in structure or expression pattern during evolution of allopolyploid Brassica juncea. We cloned AP2 orthologs and c-DNAs from B. juncea and B. nigra. B. juncea was found to carry three AtAP2 orthologs. Comparison of BjAP2 genes with AP2 orthologs from progenitor species, B. rapa and B. nigra showed that two of the BjAP2 genes were derived from B. rapa and one from B. nigra. BjAP2 genes have retained its characteristic AP2 domain and miR172 complementary sequences. mRNAs originated from three AP2 orthologs were detected in all the tissues examined, namely, leaf, flower buds and seedling, indicating absence of sub-functionalization of AP2 during polyploid evolution. However, one of the B. rapa copies gave alternatively spliced AP2 transcript which lacked the second exon. Consequently, the splice variant could not be translated into functional AP2 protein. Considering that miR172 suppresses translation of AP2 transcripts, the alternatively spliced transcript could still play important regulatory role by limiting the availability of miR172 molecules to bind to functional AP2 transcripts. qRT-PCR analysis of BjAP2 expression in different accessions of B. juncea with contrasting seed size indicated that BjAP2 is not a major determinant of seed size in mustard
Magnetopriming Actuates Nitric Oxide Synthesis to Regulate Phytohormones for Improving Germination of Soybean Seeds under Salt Stress
In this study, the role of the signalling molecule nitric oxide (NO) in magnetopriming-mediated induction of salinity tolerance in soybean seeds is established. The cross-talk of NO with germination-related hormones gibberellic acid (GA), abscisic acid (ABA) and auxin (IAA) for their ability to reduce the Na+/K+ ratio in the seeds germinating under salinity is highlighted. Salt tolerance index was significantly high for seedlings emerging from magnetoprimed seeds and sodium nitroprusside (SNP, NO-donor) treatment. The NO and superoxide (O2•−) levels were also increased in both of these treatments under non-saline and saline conditions. NO generation through nitrate reductase (NR) and nitric oxide synthase-like (NOS-like) pathways indicated the major contribution of NO from the NR-catalysed reaction. The relative expression of genes involved in the NO biosynthetic pathways reiterated the indulgence of NR in NO in magnetoprimed seeds, as a 3.86-fold increase in expression was observed over unprimed seeds under salinity. A 23.26-fold increase in relative expression of NR genes by the NO donor (SNP) was observed under salinity, while the NR inhibitor (sodium tungstate, ST) caused maximum reduction in expression of NR genes as compared to other inhibitors [L-NAME (N(G)-nitro-L-arginine methyl ester; inhibitor of nitric oxide synthase-like enzyme) and DPI (diphenylene iodonium; NADPH oxidase inhibitor)]. The ratio of ABA/GA and IAA/GA decreased in magnetoprimed and NO donor-treated seeds, suggesting homeostasis amongst hormones during germination under salinity. The magnetoprimed seeds showed low Na+/K+ ratio in all treatments irrespective of NO inhibitors. Altogether, our results indicate that a balance of ABA, GA and IAA is maintained by the signalling molecule NO in magnetoprimed seeds which lowers the Na+/K+ ratio to offset the adverse effects of salinity in soybean seeds
