Correction: Enhanced Gene Expression Rather than Natural Polymorphism in Coding Sequence of the OsbZIP23 Determines Drought Tolerance and Yield Improvement in Rice Genotypes.

[This corrects the article DOI: 10.1371/journal.pone.0150763.]

Enhanced Gene Expression Rather than Natural Polymorphism in Coding Sequence of the OsbZIP23 Determines Drought Tolerance and Yield Improvement in Rice Genotypes.

Drought is one of the major limiting factors for productivity of crops including rice (Oryza sativa L.). Understanding the role of allelic variations of key regulatory genes involved in stress-tolerance is essential for developing an effective strategy to combat drought. The bZIP transcription factors play a crucial role in abiotic-stress adaptation in plants via abscisic acid (ABA) signaling pathway. The present study aimed to search for allelic polymorphism in the OsbZIP23 gene across selected drought-tolerant and drought-sensitive rice genotypes, and to characterize the new allele through overexpression (OE) and gene-silencing (RNAi). Analyses of the coding DNA sequence (CDS) of the cloned OsbZIP23 gene revealed single nucleotide polymorphism at four places and a 15-nucleotide deletion at one place. The single-copy OsbZIP23 gene is expressed at relatively higher level in leaf tissues of drought-tolerant genotypes, and its abundance is more in reproductive stage. Cloning and sequence analyses of the OsbZIP23-promoter from drought-tolerant O. rufipogon and drought-sensitive IR20 cultivar showed variation in the number of stress-responsive cis-elements and a 35-nucleotide deletion at 5'-UTR in IR20. Analysis of the GFP reporter gene function revealed that the promoter activity of O. rufipogon is comparatively higher than that of IR20. The overexpression of any of the two polymorphic forms (1083 bp and 1068 bp CDS) of OsbZIP23 improved drought tolerance and yield-related traits significantly by retaining higher content of cellular water, soluble sugar and proline; and exhibited decrease in membrane lipid peroxidation in comparison to RNAi lines and non-transgenic plants. The OE lines showed higher expression of target genes-OsRab16B, OsRab21 and OsLEA3-1 and increased ABA sensitivity; indicating that OsbZIP23 is a positive transcriptional-regulator of the ABA-signaling pathway. Taken together, the present study concludes that the enhanced gene expression rather than natural polymorphism in coding sequence of OsbZIP23 is accountable for improved drought tolerance and yield performance in rice genotypes

Minimum inhibitory concentration (MIC) of As and other heavy metals tested for strain KAs 5-3^T and reference type strains.

<p><b>Strains:</b> 1, KAs 5-3^T; 2, <i>P</i>. <i>mexicana</i> AMX 26B^T; 3, <i>P</i>. <i>japonensis</i> 12-3^T; 4, <i>P</i>. <i>indica</i> P15^T; 5, <i>P</i>. <i>daejeonensis</i> TR6-08^T; 6, <i>P</i>. <i>suwonensis</i> 4M1^T; 7, <i>P</i>. <i>wuyuanensis</i> XC21-1^T; 8, <i>P</i>. <i>putridarboris</i> WD12^T; 9, <i>E</i>. <i>coli</i> NCIM 2931^T; 10, <i>C</i>. <i>metallidurans</i> DSM 2839^T.</p

Neighbor-joining phylogenetic tree of genes encoding arsenate reductase (<i>ars</i>C) of KAs 5-3^T with similar sequences (>90% identity) retrieved from NCBI database.

<p>Bootstraps (1000 replications) of above 50% are shown at each branch points. The sequences obtained in this study are highlighted in bold, sequence accession numbers are in parentheses.</p

Taxonomy and physiology of <i>Pseudoxanthomonas arseniciresistens</i> sp. nov., an arsenate and nitrate-reducing novel <i>gammaproteobacterium</i> from arsenic contaminated groundwater, India - Fig 2

<p><b>Growth and reductive use of different electron acceptors (NO</b>_<b>3</b>^<b>-</b><b>, NO</b>_<b>2</b>^<b>-</b><b>, As</b>^<b>5+</b><b>, Fe</b>^<b>3+</b><b>) by strain KAs 5-3</b>^<b>T</b><b>in the presence of various sugar and hydrocarbon sources as principal carbon substrates</b>: a) glucose, b) lactate, c) dodecane, and d) pentadecane.</p

Taxonomy and physiology of <i>Pseudoxanthomonas arseniciresistens</i> sp. nov., an arsenate and nitrate-reducing novel <i>gammaproteobacterium</i> from arsenic contaminated groundwater, India - Fig 2

<p><b>Growth and reductive use of different electron acceptors (NO</b>_<b>3</b>^<b>-</b><b>, NO</b>_<b>2</b>^<b>-</b><b>, As</b>^<b>5+</b><b>, Fe</b>^<b>3+</b><b>) by strain KAs 5-3</b>^<b>T</b><b>in the presence of various sugar and hydrocarbon sources as principal carbon substrates</b>: a) glucose, b) lactate, c) dodecane, and d) pentadecane.</p

Cellular fatty acid profiles of strain KAs 5-3^T and related type members of the genus <i>Pseudoxanthomonas</i>.

<p><b>Strains:</b> 1, KAs 5-3^T; 2, <i>P</i>. <i>mexicana</i> AMX 26B^T; 3, <i>P</i>. <i>japonensis</i> 12-3^T; 4, <i>P</i>. <i>indica</i> P15^T; 5, <i>P</i>. <i>daejeonensis</i> TR6-08^T; 6, <i>P</i>. <i>suwonensis</i> 4M1^T; 7, <i>P</i>. <i>wuyuanensis</i> XC21-2^T; 8, <i>P</i>. <i>putridarboris</i> WD12^T.</p

Neighbor-joining phylogenetic tree of genes encoding dissimilatory nitrate reductase (<i>nar</i>G) of KAs 5-3^T with similar sequences (>90% identity) retrieved from NCBI database.

<p>Bootstraps (1000 replications) of above 50% are shown at each branch points. The sequences obtained in this study are highlighted in bold, sequence accession numbers are in parentheses.</p