GhCYS2 governs the tolerance against cadmium stress by regulating cell viability and photosynthesis in cotton.

Cysteine, an early sulfur-containing compound in plants, is of significant importance in sulfur metabolism. CYS encodes cysteine synthetase that further catalyzes cysteine synthesis. In this investigation, CYS genes, identified from genome-wide analysis of Gossypium hirsutum bioinformatically, led to the discovery of GhCYS2 as the pivotal gene responsible for Cd2+ response. The silencing of GhCYS2 through virus-induced gene silencing (VIGS) rendered plants highly susceptible to Cd2+ stress. Silencing GhCYS2 in plants resulted in diminished levels of cysteine and glutathione while leading to the accumulation of MDA and ROS within cells, thereby impeding the regular process of photosynthesis. Consequently, the stomatal aperture of leaves decreased, epidermal cells underwent distortion and deformation, intercellular connections are dramatically disrupted, and fissures manifested between cells. Ultimately, these detrimental effected culminating in plant wilting and a substantial reduction in biomass. The association established between Cd2+ and cysteine in this investigation offered a valuable reference point for further inquiry into the functional and regulatory mechanisms of cysteine synthesis genes.

Atomically resolved probe-type scanning tunnelling microscope for use in harsh vibrational cryogen-free superconducting magnet.

We present a probe-type scanning tunnelling microscope (STM) with atomic resolution that is designed to be directly inserted and work in a harsh vibrational cryogen-free superconducting magnet system. When a commercial variable temperature insert (VTI) is installed in the magnet and the STM is housed in the VTI, a lowest temperature of 1.6 K can be achieved, at which the STM still operates well. We tested the STM in an 8 T superconducting magnet cooled with a pulse-tube cryocooler and obtained atomically resolved graphite and NbSe2 images as well as the scanning tunnelling spectrum (i.e., dI/dV spectrum) data of the latter near its critical temperature, which show the formation process of the superconducting gap as a function of temperature. The drifting rates of the STM at 1.6 K in the X-Y plane and Z direction are 1.15 and 1.71 pm/min, respectively. Noise analysis for the tunnelling current shows that the amplitudes of the dominant peaks (6.84 and 10.25 Hz) are as low as 1.5 pA.Hz-1/2 when we set the current to 0.5 nA and open the feedback loop. This is important as a cryogen-free magnet system has long been considered too harsh for any atomic resolution measurement.