The SsWRKY1 transcription factor of Saccharum spontaneum enhances drought tolerance in transgenic Arabidopsis thaliana and interacts with 21 potential proteins to regulate drought tolerance in S. spontaneum.

In this study, we characterized a WRKY family member gene, SsWRKY1, which is located in the nucleus and contains multiple stress-related cis-acting elements. In addition, constructed SsWRKY1-overexpressing Arabidopsis thaliana had higher antioxidant enzyme activity and proline content under drought stress conditions, with lower malondialdehyde content and reactive oxygen species (ROS) accumulation, and the expression levels of six stress-related genes were significantly upregulated. This indicates that the overexpression of SsWRKY1 in Arabidopsis thaliana improves resistance to drought stress. SsWRKY1 does not have transcriptional autoactivation activity in yeast cells. The yeast two-hybrid (Y2H) system and the S. spontaneum cDNA library were used to screen 21 potential proteins that interact with SsWRKY1, and the interaction between SsWRKY1 and ATAF2 was verified by GST pull-down assay. In summary, our results indicate that SsWRKY1 plays an important role in the response to drought stress and provide initial insights into the molecular mechanism of SsWRKY1 in response to drought stress.

Voltage-Polarity Dependent Programming Behaviors of Amorphous In-Ga-Zn-O Thin-Film Transistor Memory with an Atomic-Layer-Deposited ZnO Charge Trapping Layer.

Amorphous In-Ga-Zn-O (a-IGZO) thin-film transistor (TFT) memories are attracting many interests for future system-on-panel applications; however, they usually exhibit a poor erasing efficiency. In this article, we investigate voltage-polarity-dependent programming behaviors of an a-IGZO TFT memory with an atomic-layer-deposited ZnO charge trapping layer (CTL). The pristine devices demonstrate electrically programmable characteristics not only under positive gate biases but also under negative gate biases. In particular, the latter can generate a much higher programming efficiency than the former. Upon applying a gate bias pulse of +13 V/1 µs, the device shows a threshold voltage shift (ΔVth) of 2 V; and the ΔVth is as large as -6.5 V for a gate bias pulse of -13 V/1 µs. In the case of 12 V/1 ms programming (P) and -12 V/10 µs erasing (E), a memory window as large as 7.2 V can be achieved at 103 of P/E cycles. By comparing the ZnO CTLs annealed in O2 or N2 with the as-deposited one, it is concluded that the oxygen vacancy (VO)-related defects dominate the bipolar programming characteristics of the TFT memory devices. For programming at positive gate voltage, electrons are injected from the IGZO channel into the ZnO layer and preferentially trapped at deep levels of singly ionized oxygen vacancy (VO +) and doubly ionized oxygen vacancy (VO 2+). Regarding programming at negative gate voltage, electrons are de-trapped easily from neutral oxygen vacancies because of shallow donors and tunnel back to the channel. This thus leads to highly efficient erasing by the formation of additional ionized oxygen vacancies with positive charges.