Phytoextraction and Migration Patterns of Cadmium in Contaminated Soils by <i>Pennisetum hybridum</i>

This study was conducted to identify soil cadmium (Cd) removal pathways and their contribution rates during phytoremediation by Pennisetum hybridum, as well as to comprehensively assess its phytoremediation potential. Multilayered soil column tests and farmland-simulating lysimeter tests were conducted to investigate the Cd phytoextraction and migration patterns in topsoil and subsoil simultaneously. The aboveground annual yield of P. hybridum grown in the lysimeter was 206 ton·ha−1. The total amount of Cd extracted in P. hybridum shoots was 234 g·ha−1, which was similar to that of other typical Cd-hyperaccumulating plants such as Sedum alfredii. After the test, the topsoil Cd removal rate was 21.50–35.81%, whereas the extraction efficiency in P. hybridum shoots was only 4.17–8.53%. These findings indicate that extraction by plant shoots is not the most important contributor to the decrease of Cd in the topsoil. The proportion of Cd retained by the root cell wall was approximately 50% of the total Cd in the root. Based on column test results, P. hybridum treatment led to a significant decrease in soil pH and considerably enhanced Cd migration to subsoil and groundwater. P. hybridum decreases Cd in the topsoil through multiple pathways and provides a relatively ideal material for phytoremediation of Cd-contaminated acid soils

Hyperspectral Inversion Model of Relative Heavy Metal Content in <i>Pennisetum sinese Roxb</i> via EEMD-db3 Algorithm

Detection rapidity and model accuracy are the keys to hyperspectral nondestructive testing technology, especially for Pennisetum sinese Roxb (PsR) due to its extremely high adsorptive heavy metal content. The study of the resolution of PsR is conducive to the analysis of the accumulated heavy metal content in its different parts. In this paper, the contents of Cd, Cu and Zn accumulated in the old leaves, young leaves, upper stem, middle stem and lower stem, as well as the hyperspectral data of the corresponding parts, were measured simultaneously in both fresh and dry states. To begin, the spectral data of PsR were preprocessed by using Ensemble Empirical Mode Decomposition-Daubechies3 (EEMD-db3), Savitzky–Golay (SG), Symlet3 (sym3), Symlet5 (sym5), and multiplicative scatter correction (MSC). The 40 samples were divided into 32 training sets and 8 validation sets. The preprocessed spectral data were transformed by the first derivative (FD) and reciprocal logarithm (log(1/R)) to highlight the singularities using binary wavelet decomposition. After screening the significant bands from the correlation curve, the competitive adaptive reweighted sampling (CARS) and successive projection algorithm (SPA) were applied to extract the spectral characteristic variables, which were used to establish the partial least-squares (PLS) regression and multiple stepwise linear regression (MSLR) inversion models of Cd, Cu, and Zn contents. Based on EEMD-db3 pretreatment, the inversion model of Zn in the dry (fresh) state had R2 values of 0.884 (0.880), NRMSE values of 0.179 (0.253) and RPD values of 3.191 (3.221), indicating excellent stability and predictive performance. The findings of this study can not only aid in the rapid nondestructive detection of heavy metal adsorption in various parts of PsR, but can also be applied to guide the development and use of animal feed

Data_Sheet_1_Flagellin C decreases the expression of the Gossypium hirsutum cation/proton exchanger 3 gene to promote calcium ion, hydrogen peroxide, and nitric oxide and synergistically regulate the resistance of cotton to Verticillium wilt.docx

To date, no ideal effective method for controlling Verticillium wilt in upland cotton (Gossypium hirsutum) has been defined. The purpose of this study was to determine the effects and mechanism through which flagellin C (FLiC) regulates the Gossypium hirsutum cation/proton exchanger 3 gene (GhCAX3), induces plant immunity, and increases resistance to Verticillium wilt. The FLiC gene was cloned from an endophytic bacterium (Pseudomonas) isolated from roots of the upland cotton cultivar Zhongmiansuo 41. The biocontrol effects of FLiC purified in vitro on resistant and susceptible upland cotton cultivars were 47.50 and 32.42%, respectively. FLiC induced a hypersensitive response (HR) in leaves of tobacco and immune responses in upland cotton. Transcriptome data showed that treatment with FLiC significantly enriched the calcium antiporter activity-associated disease-resistant metabolic pathway in seedlings. Moreover, FLiC downregulated GhCAX3 expression to increase intracellular calcium ion (Ca2+) content and stimulate increases in the intracellular hydrogen peroxide (H2O2) and nitric oxide (NO) contents. The coordinated regulation of Ca2+, H2O2, and NO enhanced cotton resistance to Verticillium wilt. Furthermore, transgenic Arabidopsis plants overexpressing FLiC showed significantly improved resistance to Verticillium wilt. FLiC may be used as a resistance gene and a regulator to improve resistance to Verticillium dahliae (VD) in upland cotton.</p

Antagonistic Potential of Novel Endophytic Bacillus Strains and Mediation of Plant Defense against Verticillium Wilt in Upland Cotton

Verticillium wilt caused by Verticillium dahliae is a threatening disease of cotton, causing economic loss worldwide. In this study, nine endophytic Bacillus strains isolated from cotton roots exhibited inhibitory activity against V. dahliae strain VD-080 in a dual culture assay. B. altitudinis HNH7 and B. velezensis HNH9 were chosen for further experiments based on their high antagonistic activity. The secondary metabolites of HNH7 and HNH9 also inhibited the growth of VD-080. Genetic marker-assisted detection revealed the presence of bacillibactin, surfactin, bacillomycin and fengycin encoding genes in the genome of HNH7 and HNH9 and their corresponding gene products were validated through LC-MS. Scanning electron microscopy revealed mycelial disintegration, curling and shrinkage of VD-080 hyphae after treatment with methanolic extracts of the isolated endophytes. Furthermore, a significant reduction in verticillium wilt severity was noticed in cotton plants treated with HNH7 and HNH9 as compared to control treatments. Moreover, the expression of defense-linked genes, viz., MPK3, GST, SOD, PAL, PPO and HMGR, was considerably higher in plants treated with endophytic Bacillus strains and inoculated with VD-080 as compared to control