Search

Whole-genome doubling or polyploidy increases plants' tolerance to biotic and abiotic stress. Cadmium (Cd) damages the plant's metabolic system, leading to decreased plant development. The role of tetraploidy and iron nanoparticles (Fe NPs) in minimizing Cd toxicity in rice was investigated in this work. Diploid (E285) and tetraploid (T485) rice lines were treated with Cd (100 μM) and different doses of Fe NPs (0, 10, 25, and 50 mg L−1). The Cd exposure substantially decreased agronomic traits (root and shoot length, shoot and root fresh weight), chlorophyll contents, and antioxidant enzyme activity and increased reactive oxygen species (ROS). The Cd toxicity effect was more pronounced in diploid rice than in tetraploid rice. The application of Fe NPs to Cd-contaminated rice plants reversed the detrimental consequences of Cd in tetraploid and diploid rice cultivars, verified by the substantial upturn in plant growth parameters, chlorophyll contents, decreased ROS, and increased levels of antioxidant enzymes. The Cd uptake was significantly reduced by tetraploidy and Fe NPs, which negatively controlled the expression patterns of Cd transporter genes (like OsNRAMP2and OsHMA2). The strongest association was seen between diploid rice and cadmium levels in seedlings. Transmission electron microscopy revealed that Cd, especially in diploid rice, caused cell structure damage that Fe NPs and tetraploidy almost repaired. This study demonstrated that tetraploidy and Fe NPs could alleviate Cd toxicity by lowering Cd accumulation, ROS, and cell damage.

Tianma (Gastrodia elataBlume) has unique biological characteristics and high medicinal value. The wild resource of G. elatais being overutilized and should be conserved as it is already included in the list of endangered species in China. The population size of cultivated G. elatais small because of domestication bottleneck. Therefore, it is of utmost importance to evolve high-quality varieties and conserve wild resources of G. elata. In this study, we sequenced tuber transcriptomes of three major cultivated sub-species of Gastrodia elata, namely G. elata BI. f. elata, G. elata Bl. f. glauca S. Chow,and G. elata Bl. f. Viridis, and obtained about 7.8G clean data. The assembled high-quality reads of three sub-species were clustered into 56,884 unigenes. Of these, 31,224 (54.89%), 25,733 (45.24%), 22,629 (39.78%), and 11,856 (20.84%) unigenes were annotated by Nr, Swiss-Port, Eukaryotic Ortholog Groups (KOG), and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases, respectively. Here, a total of 3766 EST-SSRs and 128,921 SNPs were identified from the unigenes. The results not only offer huge number of genes that were responsible for the growth, development, and metabolism of bioactive components, but also a large number of molecular markers were detected for future studies on the conservation genetics and molecular breeding of G. elata.