De novo shoot organogenesis (DNSO) is a procedure commonly used for the in vitro regeneration of shoots from a variety of plant tissues. Shoot regeneration occurs on nutrient media supplemented with the plant hormones cytokinin (CK) and auxin, which play essential roles in this process, and genes involved in their signaling cascades act as master regulators of the different phases of shoot regeneration. In the last 20 years, the genetic regulation of DNSO has been characterized in detail. However, as of today, the CK and auxin signaling events associated with shoot regeneration are often interpreted as a consequence of these hormones simply being present in the regeneration media, whereas the roles for their prior uptake and transport into the cultivated plant tissues are generally overlooked. Additionally, sucrose, commonly added to the regeneration media as a carbon source, plays a signaling role and has been recently shown to interact with CK and auxin and to affect the efficiency of shoot regeneration. In this review, we provide an integrative interpretation of the roles for CK and auxin in the process of DNSO, adding emphasis on their uptake from the regeneration media and their interaction with sucrose present in the media to their complex signaling outputs that mediate shoot regeneration.

Soils contaminated with radionuclides pose a long-term radiation hazard to human health through food chain exposure and other pathways. The uptake, accumulation, and distribution of ¹³³Cs, individual ⁸⁸Sr, and combined ⁸⁸Sr + ¹³³Cs, with their physiological and biochemical responses in greenhouse-potted soil-based cucumber (Cucumis sativus L.), were studied. The results from the present study revealed that the uptake, accumulation, TF, and BCF ability of cucumber for ⁸⁸Sr + ¹³³Cs were greater than for ¹³³Cs and ⁸⁸Sr while the concentration was the same in the soil (10, 20, 40, 80, and 160 mg kg⁻¹). The highest ⁸⁸Sr + ¹³³Cs accumulation was 2128.5 µg g⁻¹dw, and the highest accumulation values of ¹³³Cs and ⁸⁸Sr were 1738.4 µg g⁻¹dw and 1818.2 µg g⁻¹dw (in 160 mg kg⁻¹), respectively. The lowest ⁸⁸Sr + ¹³³Cs, ¹³³Cs, and ⁸⁸Sr accumulation values were 416.37 µg g⁻¹dw, 268.90 µg g⁻¹dw, and 354.28 µg g⁻¹dw (10 mg kg⁻¹), respectively. MDA content was higher under ⁸⁸Sr and ¹³³Cs stress than under ⁸⁸Sr + ¹³³Cs stress. Chlorophyll content increased at 10 and 20 mg kg⁻¹; however, it decreased with increasing concentrations (40, 80, and 160 mg kg⁻¹). Proline content and the activities of CAT, POD, and SOD were lower under ¹³³Cs and ⁸⁸Sr than ⁸⁸Sr + ¹³³Cs stress. The ⁸⁸Sr, ¹³³Cs, and ⁸⁸Sr + ¹³³Cs treatment concentrations sequentially induced some enzymes over 60 days of exposure, suggesting that this complex of antioxidant enzymes—CAT, POD, and SOD—works in combination to reduce the impact of toxicity of ⁸⁸Sr, ¹³³Cs, and ⁸⁸Sr + ¹³³Cs, especially in young leaves. It is concluded that cucumber reveals considerable phytoremediation capabilities due to unique growth potential in contaminated substrate and is suitable for the bioreclamation of degraded soils. The plant is especially applicable for efficient phytoextraction of ⁸⁸Sr + ¹³³Cs contamination.

In order to illustrate their tolerance mechanism, four leading cultivars of Brassica napus (Mianyou 15, Guohaoyou 8, Yiyou 21, and Mianyou 16) were investigated to study the effects of Clopyralid, Benazolin, and Clethodium on physio-chemical and ultrastructural attributes of Brassica napus at during seed germination stage, by various concentrations (0.0, 0.5, 0.7, 1.0, 1.3 μg/10 mL) of Clopyralid, Benazolin, and Clethodium to rape seedlings in terms of various physiological and biochemical measurements and microscopic analysis. The main results were as follows: low concentration (0.5 μg/10 ml) of Clopyralid, Benazolin, and Clethodium had no significant effect on Brassica napus CVS. It was found that with the increasing of treated concentrations, the growth of Brassica napus was inhibited more when the concentration of Clopyralid, Benazolin, and Clethodium was higher than 1.3 μg·L-1. It inhibited the net photosynthetic rate, chlorophyll content, chlorophyll fluorescence value, and anti-enzyme activities of Brassica napus. Moreover, it increased lipid peroxidation, accumulated reactive oxygen species, and damaged the ultrastructure of chloroplasts and mitochondria in mesophyll cells. In addition, the ability of resistance to the stress of Clopyralid, Benazolin, and Clethodium in all cultivars shows higher sensitivity which is more effective. Therefore, this study defined the effect of selected herbicides on Brassica napus, and the findings have great significance in extending the calculation by field application of those herbicides.

Extreme weather and global warming are drastic agricultural issues causing water scarcity. Under these conditions, it is vital to select drought-tolerant hybrid super rice breeds to enhance the rice yield in dry areas. In the current study, a dry-shed experiment was carried out in 2019–2020 to analyze the root growth, gene expression, and enzyme activity of hybrid rice Deyou4727, its parent (Dexiang074B * Chenghui727), taking IR64 as a universal control. Results showed that Deyou4727 and its maintainer line Dexiang074B produced more roots (30–50 cm soil) and higher enzymatic activity than IR64 during the drought stress period, indicating a good drought-tolerant capacity for Deyou4727. The distribution and morphology of the root system in Deyou4727 were inherited by the maintainer line Dexiang074B, which was confirmed by the high upregulation of DRO1 and OsPIN1b gene expression and the sharing of the same ORF region in both the hybrid rice varieties. However, the DRO1 gene ORF study showed that, in the case of the control IR64, ‘A’ was missing at the 4th exon of the DRO1 gene, which may explain the shallow and weak root architecture system of IR64. The drought-tolerance capacity of Deyou4727 can be used in the future as a drought-resistant germplasm for breeding more drought-tolerant hybrid rice varieties.