Mn In Wheat Research Articles

MTP8 from Triticum urartu Is Primarily Responsible for Manganese Tolerance.

Mineral nutrients, such as manganese (Mn) and iron (Fe), play essential roles in many biological processes in plants but their over-enrichment is harmful for the metabolism. Metal tolerance proteins (MTPs) are involved in cellular Mn and Fe homeostasis. However, the transporter responsible for the transport of Mn in wheat is unknown. In our study, TuMTP8, a Mn-CDF transporter from diploid wheat (Triticum urartu), was identified. Expression of TuMTP8 in yeast strains of Δccc1 and Δsmf1 and Arabidopsis conferred tolerance to elevated Mn and Fe, but not to other metals (zinc, cobalt, copper, nickel, or cadmium). Compared with TuVIT1 (vacuole Fe transporter), TuMTP8 shows a significantly higher proportion in Mn transport and a smaller proportion in Fe transport. The transient analysis in tobacco epidermal cells revealed that TuMTP8 localizes to vacuolar membrane. The highest transcript levels of TuMTP8 were in the sheath of the oldest leaf and the awn, suggesting that TuMTP8 sequesters excess Mn into the vacuole in these organs, away from more sensitive tissues. These findings indicate that TuMTP8, a tonoplast-localized Mn/Fe transporter, functions as a primary balancer to regulate Mn distribution in T. urartu under elevated Mn conditions and participates in the intracellular transport and storage of excess Mn as a detoxification mechanism, thereby conferring Mn tolerance.

Accumulation and translocation of copper in Cu-polluted sierozem in northwest China

ABSTRACT Studies on subsequent effects of Cu pollution on mineral nutrients uptake in different tissues of crops grown in sierozem are limited. A pot experiment was conducted to reveal the effects of exogenous Cu on the accumulation and translocation of Cu and the interaction with nutrients in different tissues of wheat in Cu-polluted sierozem in northwest China. Results showed that the average concentration of Cu in different tissues of wheat was roots > stems and leaves > grains > shells. The bioaccumulation factor (BCF) of Cu in different parts of wheat was roots > stems and leaves > grains > shells. There was a weak translocation of Cu from sierozem to tops of wheat. Furthermore, the translocation ability of Cu from roots to tops of wheat was increasingly weak with increasing Cu stresses. Micronutrients (Fe, Mn and Ca) distribution in different wheat tissues indicated that uptake and upward translocation of these kinds of micronutrients could be affected by high soil Cu concentration. The addition of Cu in sierozem promoted the Mn absorption in wheat tissues, which may also be helpful to solve the lack of Mn in wheat caused by the Cu shortage in sierozem.

The effect of enzymes on release of trace elements in feedstuffs based on in vitro digestion model for monogastric livestock

BackgroundThis experiment was conducted to study the effect of different feed enzymes (phytase, xylanase, β-glucanase) on release rate of trace elements (Fe, Cu, Mn and Zn) in 6 commonly used feedstuffs (corn, wheat, barley, soybean meal, wheat bran, wheat middlings) by using an in vitro model, simulating the digestive processes in stomach for 2 h and then in small intestine for 6 h at 39 °C.ResultsPhytase raised (P < 0.05) the release rate of Cu and Zn in corn, Cu, Zn and Mn in wheat, Cu in barley, Cu, Zn and Mn in soybean meal, Zn, Fe in wheat bran and Zn, Fe, Mn in wheat middlings. The release rate of various trace elements in feedstuffs was increased after xylanase addition. Compared with the control group, the release rate of soluble Cu in corn, wheat, barley and soybean meal, soluble Zn in corn, wheat and wheat middlings and soluble of Mn in corn, wheat, barley and wheat bran increased (P < 0.05) after xylanase treatment. After the treatment of β-glucanase, the release rate of soluble Cu in corn, wheat and wheat bran, soluble Fe in barley, soybean meal and wheat bran and soluble Mn in corn and wheat bran all increased (P < 0.05) compared with the control group. In each feedstuff, after corresponding enzyme treatment, the contents of phytic acid, xylan and β-glucan were significantly lower than those of the control group (P < 0.05).ConclusionsResults showed that bound trace elements in feedstuffs can be released by feed enzymes. It may be necessary to take the trace elements in feedstuffs into account in the actual feed preparation including feed enzymes.

Prospecting plant growth promoting bacteria and cyanobacteria as options for enrichment of macro- and micronutrients in grains in rice–wheat cropping sequence

AbstractThe influence of plant growth promoting bacteria (PGPB) and cyanobacteria, alone and in combination, was investigated on micronutrient enrichment and yield in rice–wheat sequence, over a period of two years. Analysis of variance (ANOVA) in both crops indicated significant differences in soil dehydrogenase activity and micronutrient enrichment in grains (Fe, Zn in rice, and Cu, Mn in wheat). The combined inoculation of Anabaena oscillarioides CR3, Brevundimonas diminuta PR7, and Ochrobactrum anthropi PR10 (T6) significantly increased nitrogen, phosphorus, and potassium (NPK) content and improved rice yield by 21.2%, as compared to the application of recommended dose of NPK fertilizers (T2). The treatment T5 (Providencia sp. PR3 + B. diminuta PR7 + O. anthropi PR10) recorded an enhancement of 13–16% in Fe, Zn, Cu, and Mn concentrations, respectively, in rice grains. In wheat, Providencia sp. PW5 (T6) recorded the highest yield (5.23 Mg ha−1) and significantly higher enrichment of Fe and Cu (44–45%) ...

Effect of Genotype and Farming System on Concentration of Mineral Elements in Organically and Conventionally Grown Cereals/ Genotipa Un Saimniekoðanas Sistçmas Ietekme Uz Minerâlvielu Saturu Bioloìiski Un Konvencionâli Audzçtos Graudaugos

Abstract About half of the human population suffers from deficiency of mineral elements, mostly iron (Fe) and zinc (Zn). The purpose of the research was to compare the concentration of Fe and Zn in grain of 19 spring barley (in Hordeum vulgare L.) genotypes and the concentration of Zn and manganese (Mn) in grain of 19 winter wheat (Triticum aestivum L.) genotypes grown in organic and conventional management systems during two growing seasons. The average concentration of Fe in barley ranged from 32.51-86.85 mg·kg-1 and was higher under conventional management (p &lt; 0.001); the effect of genotype was significant (p = 0.014). The average concentration of Zn in barley ranged 16.79-48.51 mg·kg-1 and was significantly higher under the organic system (p &lt; 0.001); in wheat it was 21.52-29.89 mg·kg-1 with no difference between the management systems; the effect of genotype was significant (p = 0.03 and p &lt; 0.001 for barley and wheat, respectively). The average concentration of Mn in wheat ranged from 24.63-36.07 mg·kg-1 and was higher under the conventional system (p &lt; 0.001); significant differences between genotypes were observed (p &lt; 0.001). Barley and wheat genotypes with higher concentrations of the investigated elements were identified for use in breeding for improvement of grain quality. Zn concentration correlated negatively with grain yield and positively with grain protein concentration.

Plant growth promoting activity of an auxin and siderophore producing isolate of Streptomyces under saline soil conditions

A biocontrol Streptomyces isolate (C) was tested for its plant growth promoting qualities under saline conditions. Exposure to elevated osmotic strengths up to 300 mM NaCl increased dry weight and cfu/ml significantly. The isolate C produced indolyl-3-acetic acid (IAA) into the medium in the amount of 2.4 μg/ml. The amount of auxin increased after adding salt and reached to 4.7 μg/ml in 300 mM NaCl. Biosynthesis of siderophore was detectable and increased in presence of NaCl. Streptomyces isolate C showed good solubilization of tricalcium phosphate in culture medium with 92 mg/l. Solubilization decreased in presence of NaCl. Soil treatment with isolate C increased the growth and development of wheat plant in normal and saline conditions. In this treatment there were significant increases in germination rate, percentage and uniformity, shoot length and dry weight compared to the control. Applying the bacterial inocula increased the concentration of N, P, Fe and Mn in wheat shoots grown in normal and saline soil, but had non-significant effect on other micro and macronutrients concentrations. Results of this study show that Streptomyces isolate C has potential to be utilized as biofertilizer in saline soils.

Variation of tolerance to manganese toxicity in Australian hexaploid wheat

AbstractHigh concentrations of manganese (Mn), iron (Fe), and aluminium (Al) induced in waterlogged acid soils are a potential constraint for growing sensitive wheat cultivars in waterlogged‐prone areas of Western Australian wheat‐belt. Tackling induced ion toxicities by a genetic approach requires a good understanding of the existing variability in ion toxicity tolerance of the current wheat germplasm. A bioassay for tolerance to high concentration of Mn in wheat was developed using Norquay (Mn‐tolerant), Columbus (Mn‐intolerant), and Cascades (moderately tolerant) as control genotypes and a range of MnCl2 concentrations (2, 250, 500, 750, 1000, 2000, and 3000 μM Mn) at pH 4.8 in a nutrient solution. Increasing solution Mn concentration decreased shoot and root dry weight and intensified the development of toxicity symptoms more in the Mn‐intolerant cv. Columbus than in Norquay and Cascades. The genotypic discrimination based on relative shoot (54% to 79%) and root dry weight (17% to 76%), the development of toxicity symptoms (scores 2 to 4) and the shoot Mn concentration (1428 to 2960 mg kg–1) was most pronounced at 750 μM Mn. Using this concentration to screen 60 Australian and 6 wheat genotypes from other sources, a wide variation in relative root dry weight (11% to 95%), relative shoot dry weight (31% to 91%), toxicity symptoms (1.5 to 4.5), and shoot Mn concentration (901 to 2695 mg kg–1) were observed. Evidence suggests that Mn tolerance has been introduced into Australian wheat through CIMMYT germplasm having “LERMO‐ROJO” within their parentage, preserved either through a co‐tolerance to Mn deficiency or a process of passive selection for Mn tolerance. Cultivars Westonia and Krichauff expressed a high level of tolerance to both Mn toxicity and deficiency, whereas Trident and Janz (reputed to be tolerant to Mn deficiency) were intolerant to Mn toxicity, suggesting that tolerance to excess and shortage of Mn are different, but not mutually exclusive traits. The co‐tolerance for Mn and Al in ET8 (an Al‐tolerant near‐isogenic line) and the absence of Mn tolerance in BH1146 (an Al‐tolerant genotype from Brazil) limits the effectiveness of these indicator genotypes to environments where only one constraint is induced. Wide variation of Mn tolerance in Australian wheat cultivars will enable breeding genotypes for the genetic solution to the Mn toxicity problem.

Mineral nutrition of wheat, chickpea and lentil as affected by mixed cropping and soil moisture

Interspecific complementary and competitive interactions on yield and N, P, K, Fe, Zn and Mn nutrition of mixed wheat/chickpea and wheat/lentil grown in a glasshouse under normal and drought conditions, and intercropping of wheat/chickpea in the field under rainfed conditions were investigated. The results of the experiments confirmed that drought significantly decreased the growth and mineral nutrition of all plant species. Individual plant dry weights of wheat, chickpea and lentil in the glasshouse experiment, and vegetative shoot dry weight of intercropped wheat in the field experiment were significantly increased by the associated plant species as compared with their monoculture. Even though there were increases in vegetative shoot dry weight of wheat, biological and seed yield of intercropped wheat and chickpea were decreased due to the lower row number in intercropping. However, the calculated LER (Land Equivalent Ratio) was found to be higher than 1.0 for biological and seed yields, showing that intercropping of wheat and chickpea has an advantage over monoculture. In many cases, the drought × cropping system interaction on the nutrient concentrations of plant species was not significant. Results of the glasshouse study showed that P nutrition of wheat was improved by chickpea and lentil, which might result from increases in leaf acid phosphatase in mixed cropping. The release of Fe(III)-complexing compounds from the roots was higher in the sole wheat and mixed culture than that of monocultured chickpea and lentil. This improves Fe nutrition of wheat and chickpea, but those improvements were not significant. However, Zn and Mn concentrations of mixed cropped chickpea were also increased. Under the field conditions, shoot concentration of P, K, Fe, Zn and Mn in wheat were increased by intercropping. Furthermore, the concentrations of Zn and Mn in chickpea were increased by intercropping while N, P and K concentrations were decreased. In addition, the concentrations of N, P, K and Fe for wheat seeds and of Zn and Mn for chickpea were improved by intercropping. It is concluded that interspecific interaction was complementary and generally facilitated the mineral nutrition of wheat and chickpea species grown in mixed culture. Besides giving a yield advantage, intercropping of chickpea and wheat also had a positive effect on seed mineral composition.

Uptake and distribution of65Zn and54Mn in wheat grown at sufficient and deficient levels of Zn and Mn II. During grain development

We investigated the uptake and distribution of Zn and Mn in wheat during grain development. Plants were grown in a chelate-buffered nutrient solution with one of the following treatments: control, low Zn or low Mn. Plants were dual-labelled with 65 Zn and 54 Mn at 2 and 8wk post-anthesis for 5 and 24 h, respectively. After labelling, the plants were separated into individual components for analysis. In the plants harvested at 8wk after anthesis, spikelets were separated into individual structures and analysed for radioactivity. Little or no root-supplied 54 Mn was distributed to the leaves of both the controls and low-Mn plants during the grain development stages studied here. More 54 Mn was distributed to the head at 8 wk than at 2 wk post-anthesis. In contrast, root-supplied 65 Zn was transported to the leaves at 2 and 8 wk post-anthesis. More 65 Zn was distributed to the leaves of the low-Zn plants than the controls during grain development. More 65 Zn was detected in the head towards grain maturity. Relatively larger amounts of 54 Mn than 65 Zn were found in different parts of the florets. Labelled Mn was found in relatively large quantities in the palea, lemma and in the glumes, even though most 54 Mn was found in the grain. A large percentage of the grain 54 Mn was in the outer pericarp. During grain development leaves may still require Zn but not Mn, which may be due to the requirement of Zn in maintaining membrane structure and function. Distribution of Zn and Mn within the spikelets suggests that Zn may enter the grain via the phloem while Mn may enter the grain via the xylem.

Recurrent selection for mineral content in wheat and barley

Three cycles of recurrent selection were completed for 89Sr content of grain in wheat and barley. The purposes were to ascertain the gain that could be achieved in three cycles of selection and to learn about correlated changes in content of other mineral elements. In each species selection was bidirectional resulting in two populations, one high and one low in 89Sr content. In wheat each cycle of selection resulted in genetic gain. The average response per cycle was 7.4±2.6% in the high population and -12.4±1.5% in the low population. In barley gain was achieved in cycles 1 and 2. The average response per cycle was 12.2±3.8% in the high population and -11.2±4.9% in the low population. The heritability of 89Sr content in the F2 generation was 24% and 38% in the high and low populations of wheat and 31% and 34% in the high and low populations of barley, respectively. Selection for Sr content in grain caused correlated changes in Sr content in other plant parts. In wheat there was a negative correlated response in Sr content in mature leaves, while seedling plants in in the two populations did not differ. In barley, leaf Sr content was unaffected, but seedling plants in the high and low populations differed significantly. Correlated changes in Ca content tended to parallel changes in Sr content in all plant parts in both species. Selection for grain Sr also affected P, K, Mg and Mn in wheat, and K, Mg and Na in barley. These correlated responses were not always consistent with the direction of Sr selection among plant parts or between species.