MicroRNAs (miRNAs) are non-coding small RNAs that regulate gene expression by translational repression or transcript degradation. Thus far, a large number of miRNAs have been identified from model plant species and the quantity of miRNAs has been functionally characterized in diverse plants. However, the molecular characterizations of the conserved miRNAs are still largely elusive in wheat. In this study, 32 wheat miRNAs (TaMIRs) currently released in the Sanger miRBase (the microRNA database) were selected to evaluate the expression patterns under conditions of non-stress (CK) and salt stress treatment. Based on the analysis of semiquantitative RT-PCR and quantitative real qRT-PCR, TaMIR159a, TaMIR160, TaMIR167, TaMIR174, TaMIR399, TaMIR408, TaMIR11124 and TaMIR1133 were found to have responses to salinity stress, with an upregulated pattern under salt stress treatment. Based on a BLAST search against the NCBI GenBank database, the potential targets of the salt-inducible wheat miRNAs were predicted. Except for TaMIR399 not being identified to have the putative target genes, other salt-inducible TaMIRs were found to possess 2 to 7 putative target genes. Together, our results suggest that a subset of miRNAs are involved in the mediation of salt stress signaling responses in wheat via their roles on the regulation of acted target genes at post-transcriptional and translation levels.
The E3 ubiquitin ligase is a multi-functional protein that performs vital roles, particularly in various stress environment. To further understand the biological significance of E3 ubiquitin ligase gene from wheat (
This research was conducted to explore genetic material that can yield better under salt stress conditions. The experiment was laid out using 27 upland cotton genotypes in a RCBD 2 factorial arrangement with two replications. Saline water (NaCl at 20 dS/m) was applied after satisfactory emergence was achieved. The crop was raised to maturity and data relating to yield, fiber quality and ionic traits were recorded. Analysis of variance showed significant variations in the germplasm. Plant height, bolls per plant, boll weight, GOT%, staple length, staple strength, K+ and K+/Na+ ratio under salinity stress showed a highly significant correlation with seed-cotton yield. The highest direct effect on seed-cotton yield per plant was exhibited by bolls per plant and boll weight. The results from the correlation and path coefficient analyses revealed that although the K+/Na+ ratio had a strong positively significant association with seed-cotton yield, its direct effect on the seed-cotton yield was negative and thus selection on the basis of K+/Na+ may not be fruitful. Hence, only indirect selection through bolls per plant and boll weight may be effective in increasing the seed-cotton yield per plant under salinity stress.
Two cDNA libraries for wheat near-isogenic line Tc
A maize F2 population was first used to construct a genetic linkage map of Chromosome 6 covering 117.6 cM with an average interval of 3.68 cM between adjacent markers. Based on composite interval mapping (CIM), the quantitative trait loci (QTL) for phosphorus absorption efficiency (PAE) and root-related traits was detected in four environments, i.e., Kaixian County under deficient phosphorus (KXDP), Kaixian County under normal phosphorus (KXNP), SUDP1, and SUDP2. QTLs affecting root weight (RW) were detected simultaneously at the dupssr15 locus region (bin 6.06) on Chromosome 6 in the four environments, while QTL affecting taproot length and fiber number was only detected in one or two environments. The result suggested that taproot length and fiber number were more easily affected by the environment than PAE and RW. The alleles originating from 082 increased PAE and RW on Chromosome 6. The QTL on bin 6.06 explained 4%–10% and 4%–8% of the total phenotypic variance of PAE and RW, respectively, and the estimates of the genetic effects presented dominance and overdominance. The QTL for RW in the dupssr15 locus is the minor QTLs environment interactive effects, which should be particularly useful in MAS manipulation of breeding maize.
The APETALA2 (AP2) domain defines a large family of DNA binding proteins. It has been demonstrated that the AP2 proteins have important functions in the transcriptional regulation of a variety of biologic processes related to growth and development in various responses to drought and other abiotic stresses. In this essay, recent researches on the AP2 transcription factors, such as the molecular characterization, expression patterns in responses to drought and other abiotic stresses, the roles of ABA on drought responding which were mediated by AP2 transcription factors, transcription regulation mechanisms, and the roles of overexpression of AP2 transcription factor on plant drought tolerance, etc. have been overviewed. Deepening the understanding of signaling and the corresponding transduction pathways that are initiated via drought stress stimuli will play crucial roles for providing the theoretical basis for variety breeding with promising drought tolerance in the future.