Low phosphorus availability is a major abiotic factor constraining wheat growth. The molecular mechanisms of the wheat whole genome under low-phosphorus stress are still unclear. To obtain information on gene expression in wheat seedlings under low-phosphorus stress, transcriptome sequencing was performed on roots and leaves. The results showed that 2,318 (1,646 upregulated and 672 downregulated) transcripts were differentially expressed in the leaves, and 2,018 (1,310 upregulated and 708 downregulated) were differentially expressed in the roots. Further analysis showed that these differentially expressed genes (DEGs) were mainly enriched in carbon fixation in photosynthetic organs and in carbon metabolism, photosynthesis, glyoxylate and dicarboxylate metabolism and plant-pathogen interaction in both leaves and roots. These pathways were mainly associated with environmental adaptation, energy metabolism and carbohydrate metabolism, suggesting that the metabolic processes were strengthened in wheat seedlings under low-phosphorus stress and that more energy and substances were produced to resist or adapt to this unfavourable environment. This research might provide potential directions and valuable resources to further study wheat under low-phosphorus stress.

In China, the average soil organic carbon (SOC) content of cultivated land is 30% less than the world average. Therefore, cultivation management-induced changes in SOC dynamics are necessary, especially in estuarine alluvial islands, where the SOC stocks are limited. We studied the effect of different combinations of tillage, fertilization and straw return on C distribution in different soil aggregates and on crop yield on an estuarine alluvial soil in eastern China. Compared to conventional tillage, conservation tillage (no-tillage coupled with straw return) increased water-stable large macroaggregates (>2 mm) by 35.18%, small macroaggregates (2–0.25 mm) by 33.52% and microaggregates by 25.10% in the topsoil (0–20 cm). The subsoil (20–40 cm) also showed the same trend. Compared to conventional tillage without straw return, large and, small macroaggregates and microaggregates in conservation tillage were increased by 24.52%, 28.48% and 18.12%, respectively. Straw return also caused a significant increase in aggregate-associated carbon (aggregate-associated C). No-tillage coupled with straw return had more total aggregate-associated C within all the aggregate fractions in the topsoil. But the different is that conventional tillage with straw return resulted in more aggregate-associated C than conservation tillage in the subsoil. No-tillage combined with straw return (T8) produced the highest carbon preservation capacity (CPC) of macroaggregates and microaggregates in the topsoil. A considerable proportion of the SOC was found to be stocked in the small macroaggregates under both topsoil (74.56%) and subsoil (67.09%). The CPC was highest (19.17 g·kg⁻¹) in small macroaggregates. However, no-tillage and straw return had less potential to sustain crop yield than did the conventional tillage practices; with the average rice and wheat yield correspondingly decreased by 10.63% and 7.82% in three years.

Cadmium (Cd) is highly toxic to living organisms. This study aimed to elucidate the regulation of gene expression in rice shoots under Cd stress. Rice plants were exposed to 0, 50, 75, 100 μmol/L CdCl₂ in hydroponic culture for 7 d. Transcriptional changes in rice shoots were examined by transcriptome sequencing techniques. A total of 2197 DEGs (987 up-regulated and 1210 down-regulated) were detected in rice shoots under the exposure of 75 μmol/L CdCl₂. GO and KEGG enrichment analyses showed that genes encoding auxin-responsive protein IAA and peroxidase were up-regulated, while genes encoding proteins involved in signal transduction, including TIFY family, ERF and bZIP were down-regulated. Abundant ROS related terms were also identified and grouped into significantly differentially expressed GO terms, including oxidoreductase activity, catalytic activity, oxidation-reduction process, confirming the enhanced oxidative stress of Cd. Genes encoding photosystem I reaction center subunit and photosynthetic NDH subunit of luminal location were up-regulated in pathway of energy metabolism, suggesting an interference of photosynthesis by Cd stress. Our results improve the understanding of the complex molecular responsive mechanisms of rice shoots under Cd stress.