Transfer factors of (134)Cs to crops from Typic Haplustept under tropical region as influenced by potassium application

Comparative transcriptomics analysis of potassium uptake pathways mediated cesium accumulation differences and related molecular mechanisms in Brassica juncea and Vicia faba

To analyze the differences between high- and low-accumulation plants in cesium (Cs) uptake and its related mechanism, Brassica juncea (a hyperaccumulation plant for Cs) and Vicia faba (a low-accumulation plant for Cs) were selected as comparative experimental materials. The contributions to Cs uptake of a K-transporter-mediated high-affinity transport system and a K-channel-mediated low-affinity transport system in the two plants were compared and analyzed. The difference between the two plants in the mechanism of Cs uptake was further analyzed using transcription sequence technology. The results show that the transfer characteristics of Cs in the two plants had a similar distribution relationship with K. The contribution rate of the K-channel pathway to Cs uptake was 32.00% in the V. faba seedling roots, which was significantly higher than for B. juncea (9.81%) (P < 0.01); the contribution rate of the K-transporter pathway to Cs uptake of the B. juncea seedlings was 32.08%, which was significantly higher than that of the V. faba seedlings (17.13%)(P < 0.05). Other uptake pathways also mediated the uptake of Cs by roots in B. juncea and V. faba (contribution rate: 54.92-60.09% and 42.18-59.73%, respectively). The transcriptome sequencing results confirmed that Cs-induced treatment significantly inhibited the expression of the K-transporter protein and K-channel protein-related genes in the V. faba roots, but it had no significant effect on the expression of related genes in the B. juncea roots. Thus, one reason for the significant difference between the two plant in the accumulation of Cs is that Cs inhibited the expression of related transporter protein genes in the V. faba roots.

Soil to leaf transfer factor for the radionuclides ²²⁶Ra, ⁴⁰K, ¹³⁷Cs and ⁹⁰Sr at Kaiga region, India

Transfer factors are the most important parameters required for mathematical modeling used for environmental impact assessment of radioactive contamination in the environment. In this paper soil to leaf transfer factor for the radionuclides ⁴⁰K, ²²⁶Ra, ¹³⁷Cs and ⁹⁰Sr is estimated for Kaiga region in Karnataka state, India. Among the plants in which study is carried out, ²²⁶Ra, ⁴⁰K, ¹³⁷Cs and ⁹⁰Sr activity in leaves of herbaceous plants is higher than that of tree leaves. Soil to leaf transfer factor for ²²⁶Ra, ⁴⁰K, ¹³⁷Cs and ⁹⁰Sr was found to be in the range of 0.03-0.65, 0.32-8.04, 0.05-3.03 and 0.42-2.67 respectively.

Arbuscular mycorrhizal fungi decrease radiocesium accumulation in Medicago truncatula

The role of arbuscular mycorrhizal fungi (AMF) in plant radiocesium uptake and accumulation remains ambiguous. This is probably due to the presence of other soil microorganisms, the variability of soil characteristics and plant nutritional status or the availability of its chemical analogue, potassium (K). Here, we used an in vitro culture system to study the impact of increased concentration of K on radiocesium accumulation in non K-starved mycorrhizal and non-mycorrhizal Medicago truncatula plants. In the presence of AMF radiocesium uptake decreased regardless of the concentration of K, and its translocation from root to shoot was also significantly lower. Potassium also reduced the accumulation of radiocesium in plants but to a lesser extent than mycorrhization, and without any effect on translocation. These results suggest that AMF in combination with K can play a key role in reducing radiocesium uptake and its subsequent translocation to plant shoots, thereby representing good potential for improved phytomanagement of contaminated areas.