Cadmium (Cd) is a kind of heavy metal. Cadmium pollution in paddy fields will accumulate a large amount of cadmium in rice, which will affect the growth and development of rice. In addition, long-term consumption of rice contaminated with Cd can harm human health. In this study, four rice varieties with high Cd accumulation (S4699, TLY619, JHY1586, QLY155) and four varieties with low Cd accumulation (YY4949, CYJ-7, G8YXSM, MXZ-2) were screened through field experiments for two consecutive years (2021 and 2022) and differences in antioxidant enzyme systems and expression of genes in their organs were analyzed. The total Cd content showed as follows: indica rice > japonica rice, high-Cd-accumulation variety > low-Cd-accumulation variety, and the total Cd content of each organ of rice showed root > stem > leaf > grain. The results of the antioxidant enzyme system showed that the contents of malondialdehyde (MAD), reduced glutathione (GSH), oxidized glutathione (GSSH), and peroxidase (POD) were positively correlated with the total Cd content in rice, and superoxide dismutase (SOD) showed the opposite performance in the leaves. There was no correlation between catalase (CAT) and Cd content, but CAT content decreased in leaves and grains and increased in roots and stems with increasing fertility. Based on this study, RT-qPCR was used to further validate the expression of Cd-uptake-related genes in different rice varieties. It was found that high expression of OsHMA3, OsCCX2, OsNRAMP5, and OsHMA9 genes promoted Cd uptake and translocation in rice, especially in rice varieties with high Cd accumulation. The high expression of OslRT1, OsPCR1, and OsMTP1 genes hindered Cd uptake by rice plants, which was especially evident in low-accumulating Cd rice varieties. These results provide an important theoretical reference and scientific basis for our in-depth study and understanding of the mechanism of cadmium stress tolerance in rice.

Mechanized production plays an important role in fulfilling food security demands during the period of labor shortage. Despite its benefits, the mechanical transplanted method (MET) has not been widely adopted due to a lack of awareness. Thus, this study aimed to evaluate the effect of the MET, the manual transplanted method (MAT), and the directed seeded method (DS) on rice yield and quality in farmers’ fields. A two-years field experiment (2016 and 2017) and a one-year survey (2020) were conducted to compare rice yield and quality among the MAT, MET, and DS methods. MET exhibited a higher-yielding population, increased biomass production, enhanced yield, and improved grain quality, compared with MAT. Moreover, japonica rice in MET (MET-JR) produced the maximum yield, 0.6 t hm⁻² to 3.1 t hm⁻² higher than in other treatments. However, japonica rice showed a poorer appearance quality than indica rice, as well as large panicle size (grains number per panicle ≥ 190); hybrid indica rice (HIR) also presented a high yield with poor appearance quality. These results confirmed that the application of MET could be useful in attaining high panicles per m², high biomass production, high rice yield, and considerably improved rice quality in farmers’ fields under labor shortage circumstances. Furthermore, it is also imperative to consider balancing the yield and quality of japonica rice and large panicle HIR and employing MET at a broader scale in China, as well as other developing countries having rice–based cropping systems.

Epstein-Barr virus (EBV) encodes more than 40 miRNAs that target cellular mRNAs to aid its infection, replication, and maintenance in individual cells and in its human host. Importin-7 (IPO7), also termed Imp7 or RanBPM7, is a nucleocytoplasmic transport protein that has been frequently identified as a target for two of these viral miRNAs. How the viral life cycle might benefit from regulating IPO7 has been unclear, though. We demonstrate with CRISPR-Cas9 mutagenesis that IPO7 is essential in at least three cells lines and that increasing its levels of expression inhibits growth of infected cells. EBV thus regulates the level of IPO7 to limit its accumulation consistent with its being required for survival of its host cell.