Identification of Rice Transcription Factors Associated with Drought Tolerance Using the Ecotilling Method

The drought tolerance (DT) of plants is a complex quantitative trait. Under natural and artificial selection, drought tolerance represents the crop survival ability and production capacity under drought conditions (Luo, 2010). To understand the regulation mechanism of varied drought tolerance among rice genotypes, 95 diverse rice landraces or varieties were evaluated within a field screen facility based on the ‘line–source soil moisture gradient’, and their resistance varied from extremely resistant to sensitive. The method of Ecotype Targeting Induced Local Lesions in Genomes (Ecotilling) was used to analyze the diversity in the promoters of 24 transcription factor families. The bands separated by electrophoresis using Ecotilling were converted into molecular markers. STRUCTURE analysis revealed a value of K = 2, namely, the population with two subgroups (i.e., indica and japonica), which coincided very well with the UPGMA clusters (NTSYS-pc software) using distance-based analysis and InDel markers. Then the association analysis between the promoter diversity of these transcription factors and the DT index/level of each variety was performed. The results showed that three genes were associated with the DT index and that five genes were associated with the DT level. The sequences of these associated genes are complex and variable, especially at approximately 1000 bp upstream of the transcription initiation sites. The study illuminated that association analysis aimed at Ecotilling diversity of natural groups could facilitate the isolation of rice genes related to complex quantitative traits

Two-dimensional GeP3 as a high capacity electrode material for Li-ion batteries

Two-dimensional (2D) materials are promising for use in lithium (Li) electrodes due to their high surface ratio. By using density functional theory (DFT) calculations, we investigate the adsorption and diffusion of Li on a newly predicted 2D GeP3 material [Nano Lett., 2016, 17, 1833]. The most favourable adsorption sites for Li are identified, and a semiconducting to metallic transition induced by Li adsorption is found, which indicates excellent electrical conductivity. The GeP3 monolayer has an estimated capacity of 648 mA h g−1, which is almost twice that of commercially used graphite (375 mA h g−1). During full Li intercalation, the GeP3 layer undergoes only 1.2% lattice parameter reduction. Moreover, GeP3 possesses the advantages of a small diffusion barrier (∼0.5 eV) and low average open-circuit voltages (∼0.4 V). Our results highlight a new class of promising anode materials, i.e. 2D phosphide, as potential rechargeable lithium batteries with ultrahigh-capacity, superior ionic conductivity, and low average open-circuit voltage

Transcription factor families for Ecotilling.

<p>Transcription factor families for Ecotilling.</p

Multiple comparisons among means of accessions grouped by the alleles of associated markers.

a<p>Means followed by different letters were significantly different by the LSD test at the level P≤0.05 (in lowercases) and P≤0.01 (in uppercases).</p

Basic information on the tested cultivated rice.

<p>Basic information on the tested cultivated rice.</p

UPGMA clustering of 95 rice accessions.

<p>A, clustering based on TILLING markers of promoters; B, clustering based on InDel loci. The arrows indicate the accessions being clustered into opposite sub-populations between two trees. The horizontal axis represents the coefficient of similarity.</p

Posterior probabilities (Ln <i>P</i>(D)) from six parallel calculations for each hypothetic number of subpopulations (K) in the range of K = 1 to K = 10.

<p>Posterior probabilities (Ln <i>P</i>(D)) from six parallel calculations for each hypothetic number of subpopulations (K) in the range of K = 1 to K = 10.</p

Sequence complexity of associated genes from five varieties.

<p>Black lines represent an insertion. Broken lines represent the repeat of the insertion. The arrows indicate that one or more than one site of <i>cis</i>-acting regulatory DNA elements were inserted into the promoters. The abscissa represents the distance to the transcription start sites.</p

The results of associated analysis between transcription factor promoters and DT traits during drought treatment.

<p>The results of associated analysis between transcription factor promoters and DT traits during drought treatment.</p