Effects of two species of inorganic arsenic on the nutrient physiology of rice seedlings

Abstract

This paper reports on a hydroponics experiment that was conducted to investigate the effect of inorganic arsenics on the seedlings of the rice cultivar Shanyou63. The seedlings were subjected to two treatments, i.e., As(III) and As(V). The results showed that the morphological traits of the seedlings were significantly altered after the arsenic treatments. Analysis of nitrogen, phosphorus, potassium, and arsenic contents of the roots and leaves of the seedlings indicated that the absorption of phosphorus and potassium was mainly affected by As(III), while that of nitrogen was mainly affected by As(V). The expression of 12 genes involved in the absorption and utilization of nitrogen, phosphorus, and potassium were all observed to be down-regulated after the arsenic treatments. As(V) significantly affected the absorption and utilization of nitrogen, while As(III) significantly affected those of phosphorus and potassium. The result obtained by realtime FQ-PCR regarding the difference in the gene expressions agreed with that of our hydroponics experiment.

Arsenic–silicon priming of rice (Oryza sativa L.) seeds influence mineral nutrient uptake and biochemical responses through modulation of Lsi-1, Lsi-2, Lsi-6 and nutrient transporter genes

“…In this study, we observed down regulation of AMT1 in shoots and roots at 7 d under As (III) stress. The down regulation of AMT1 was also reported in rice, lotus and mustard during As, drought and cold stress 25 , 46 , 50 . Further, at 15 d we observed upregulation of AMT1 in root under As (III) stress, again the enhanced expression of AMT1 during As (III) stress was not positively correlated with N content in plant root.…”

“…The ammonium reduced from nitrite subsequently assimilated into glutamine and then glutamate by glutamine synthetase (GS) and glutamate synthetase (GAGOT). Abiotic stress such as salt, drought, extreme cold and heavy metal leads to the down regulation of NRT2 and affects N uptake and assimilation in mustard and rice 25 , 46 . In the present study, result revealed downregulation of NRT2 gene in roots at 7 d, while upregulation was observed in roots at 15 d during As (III) stress, compared to control.…”

“…Rice, being a staple food considered as the principal source of nutrients, and As reduces the nutrient content in rice grains 24 . It also affect the expression of genes of N, P, and K metabolizing enzymes such as nitrate reductase (NR), nitrite reductase (NiR), glutamine synthetase (GS) and glutamate synthetase (GOGAT)] including their transporters such as NRT and AMT 25 . Although, the uptake, transport, and assimilation of N, P, and K in plants are well documented 26 – 28 , but the underlying mechanism in the presence of Si and As is still unclear.…”

Comparative Proteomic Analysis of Rice Shoots Exposed to High Arsenate

“…Although studies on rice abiotic stress responses have been extensively carried out (Gao et al ), there are very few focusing on the arsenic response. In the last decade, numerous morphological, physiological and biochemical analyses have been conducted to investigate the responsive behavior of rice to arsenic (Marin et al ; Abedin and Meharg ; Ahsan et al ; Azad et al ; Shri et al ; Wang et al ). Excess arsenic can cause oxidative stress (Ahsan et al ; Shri et al ), which may inhibit seed germination (Abedin and Meharg ; Shri et al ), interfere with photosynthesis (Marin et al ), suppress growth, and eventually reduce grain yield in rice (Azad et al ; Wang et al ).…”

“…In the last decade, numerous morphological, physiological and biochemical analyses have been conducted to investigate the responsive behavior of rice to arsenic (Marin et al ; Abedin and Meharg ; Ahsan et al ; Azad et al ; Shri et al ; Wang et al ). Excess arsenic can cause oxidative stress (Ahsan et al ; Shri et al ), which may inhibit seed germination (Abedin and Meharg ; Shri et al ), interfere with photosynthesis (Marin et al ), suppress growth, and eventually reduce grain yield in rice (Azad et al ; Wang et al ). The mechanisms of arsenic uptake, translocation, extrusion, distribution and compartmentalization in rice have also been studied (Abedin et al ; Meharg and Jardine ; Ali et al ; Duan et al ; Williams et al ; Xu et al ; Zhao et al ).…”