Search

Objective Soil contamination by cadmium (Cd) and lead (Pb) is a great environmental concern for food safety, and breeding cultivars that can reduce their uptake is one way to grow crops in Cd-and Pb-contaminated soils. In this paper, we experimentally studied how wheat lines with different phosphorus (P) uptake affect their uptake, translocation and accumulation of P, Cd and Pb in the crops. Method The experiment consisted of a lab part and a field part. The lab part considered one factor -- wheat varieties, and the field part was arranged randomly in soil that had been moderately contaminated by Cd and Pb. In both parts, we measured Cd and Pb uptake and their subsequent translocation. Result The average P content in the roots of lines with high P (HP) use efficiency was 7.69 mg/g, significantly lower than that in the lines with low P (LP) use efficiency, which was 8.36 mg/g (P<0.05). The average P content in the shoots of HP varieties was 9.73 mg/g, significantly higher than the 8.19 mg/g in the LP cultivars (P<0.05). The transport coefficient of P in HP varieties was 1.45, significantly higher than the 1.19 of the LP varieties (P<0.05). The kinetic uptake of Cd and Pb by roots and their translocation to shoots followed Michaelis- Menten equation (R2>0.94), with the maximum absorption rates (Vmax) and the Michaelis constants (Km) differing significantly between varieties (P<0.05). The Vmax of the roots of HP varieties was 23.9 and 411 μg/(g·d), respectively, for Cd and Pb, in comparison with 80.0 and 835 μg/(g·d) (P<0.01) for the LP lines. In contrast, Vmax for Cd and Pb in the shoots of the HP varieties was much higher than that for the LP varieties. The difference in Km between the HP and LP varieties was consistent with their difference in Vmax. Correlation analysis showed that the transport coefficients of both Cd and Pb were negatively correlated with root P content (r=-0.638 and -0.714, respectively) at significant level. The transport coefficient of Cd was positively correlated with P transport coefficient (r=0.671, P<0.01). The Pb transport coefficient was also positively correlated with P transport coefficient though not at significant level (r=0.391, P>0.05). The increase in root P content helps reduce the translocation of Cd and Pb; an increase in translocation coefficient of P did not show a noticeable impact on Pb translocation, but significantly boosted Cd transport from roots to the shoots. Conclusion The roots of LP varieties showed high uptake but low translocation of P, Cd and Pb, as opposed the HP varieties which showed a low uptake but high translocation. This suggests that LP varieties are more suitable for growing in soils contaminated by Cd and/or Pb. [ABSTRACT FROM AUTHOR]

Zinc (Zn) deficiency caused by inadequate dietary intake is a global nutritional problem, so increasing Zn concentrations in crops is a challenging and high-priority research task. A field experiment was conducted to explore the effects of nitrogen (N) fertilizers on Zn absorption and translocation in winter wheat during the 2010–2011 and 2011–2012 crop seasons, in Xinzheng City, Henan Province, China. N was applied at four levels (0, 90, 180, and 270 kg N ha−1) and Zn was applied at two levels (15 and 30 kg zinc sulfate heptahydrate (ZnSO4·7H2O) ha−1]. The results indicated that reasonable N application increased grain yield, total Zn accumulations, and Zn concentrations of each plant part of winter wheat. Furthermore, appropriate N application increased Zn distribution proportions in grains and decreased Zn distribution proportions in roots, stems, leaves, and spikes, and enhanced Zn removal from roots, stems, leaves, and spikes to grains. Meanwhile, reasonable N combined with higher Zn application had a better effect on Zn absorption and Zn translocation to grain of winter wheat. The results suggested that suitable quantity of N fertilizer combined with higher Zn application is an important measure to obtain both higher grain yield and grain Zn concentration in winter wheat production. [ABSTRACT FROM AUTHOR]

A hydroponic trial was conducted to assess interaction of molybdenum (Mo) and phosphorus (P) on uptake and translocation of P and Mo by Brassica napus. Molybdenum was applied at four rates (0, 0.01, 0.1 and 1 mg L-1) and P at three rates (1, 30, and 90 mg L-1) in nutrient solution. The results indicated that P increased shoot growth and 0.01 mg L-1 Mo improved the growth of shoots and roots. Molybdenum increased shoot P uptake and root P concentration and uptake when higher P was provided, and had a stimulating effect on P translocation from shoots to roots. P increased shoot Mo concentration and uptake, decreased those in roots, and enhanced Mo transport from roots to shoots. These results implied that both Mo and P had beneficial effects on Mo and P absorption and translocation and co-application of them were necessary to promote growth and utilization of Mo and P for Brassica napus. [ABSTRACT FROM AUTHOR]

Numerous studies have explored the effects of background music on reading comprehension, however, little is known about how native language (L1) lyrics and second language (L2) lyrics in background music influence reading comprehension performance for college students. The present study used a mixed experimental design to examine the effects of listening habits (between-participants variable: non-listeners or listeners), music type (between-participants variable: L1 (Mandarin) pop music, L2 (English) pop music or no music) and text language (within-participants variable: L1 or L2) on reading comprehension of college students in East China. A total of 90 participants (50 females) were screened into non- listeners ( n  = 45) and listeners ( n  = 45), and then were randomly assigned to one of three groups: Mandarin pop music group ( n = 30), English pop music group ( n  = 30) and no music group ( n  = 30). The results showed that reading comprehension performance was negatively affected by music with lyrics compared to the no music condition. Furthermore, Chinese/English reading comprehension was reduced more by pop music in the same language as the written texts. As expected, non-listeners were more negatively affected by music with lyrics than listeners. For both listeners and non-listeners, average reading comprehension accuracy rates were the lowest in the condition of music with native language lyrics. Overall, our research findings indicate that listening to pop music with lyrics reduces reading comprehension performance. However, listening to background music cause much less distraction if the students commonly listen to music while reading. The current study supports the duplex-mechanism account of auditory distraction., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Sun, Sun, Li, Shao, Liu and Liu.)