The concentrations and distribution of phytic acid-phosphorus and other mineral nutrients in wild-type and low phytic acid1-1 (lpa1-1) corn (Zea mays L.) grains and grain parts

2005 ◽  
Vol 83 (1) ◽  
pp. 131-141 ◽  
Author(s):  
Lan Lin ◽  
Irene Ockenden ◽  
John NA Lott

A comparison of mineral nutrient and phytic acid-phosphorus (PA-P) distribution in the grains of wild-type (WT) and low phytic acid1-1 (lpa1-1) corn (Zea mays L.) was conducted to determine how the lpa1-1 mutation influences mineral element concentrations in different grain parts and impacts the structure of phosphorus-rich inclusions (globoids) in the grain cells. This is the first report regarding total phosphorus (P) and PA-P concentrations in scutellum and root-shoot axis portions of cereal embryos of WT in comparison to its matching lpa1-1 genotype. In WT, 95% of the grain PA-P was located in the embryo, mostly in the scutellum. The lpa1-1 mutation reduced whole-grain PA-P by 62% but influenced the scutella more than the root-shoot axes and rest-of-grain fractions. In spite of the lpa1-1 mutants containing greatly reduced PA-P, whole-grain amounts of Mg, Fe, and Mn were higher in lpa1-1 than in WT, K and Zn were similar, and Ca was lower. Iron was 1/3 higher in lpa1-1 grains than WT while Ca was 18% lower. Decreased phytic acid in lpa1-1 grains resulted in reduction in globoid size in both scutellum and aleurone layer cells. Most lpa1-1 aleurone globoids were non-spherical and scutellum globoids were clusters of small spheres while WT globoids were large discrete spheres. X-ray analyses of globoids in both grain types revealed major amounts of P, K, and Mg and traces of Ca, Fe, and Zn. Both grain types contained almost no mineral nutrient stores in the starchy endosperm.Key words: corn (Zea mays L.), phytic acid-phosphorus, low phytic acid1-1 (lpa1-1) grains, mineral nutrients, globoids, electron microscopy.

2005 ◽  
Vol 83 (12) ◽  
pp. 1599-1607 ◽  
Author(s):  
Charlie Joyce ◽  
Andrea Deneau ◽  
Kevin Peterson ◽  
Irene Ockenden ◽  
Victor Raboy ◽  
...  

Concentrations of P, phytic acid (myo-inositol hexakisphosphate, IP6), and other mineral storage elements were studied in wild-type and low phytic acid (lpa) genotype Js-12-LPA wheat (Triticum aestivum L.) embryos and rest-of-grain fractions. Environmental scanning electron microscopy images revealed a decreased average size and an increased number of aleurone layer globoids in lpa grains compared with the wild type. Energy-dispersive X-ray analyses of unfixed aleurone layer and scutellum cell cytoplasm revealed mainly C, O, P, K, and Mg in both grain types. The starchy endosperm contained virtually no P, K, or Mg, demonstrating no shift of mineral nutrients to that compartment. Scanning transmission electron microscopy – energy-dispersive X-ray analyses of scutellum and aleurone layer globoids in both genotypes revealed that P, K, and Mg were the main mineral nutrients in globoids with low amounts of Ca, Fe, and Zn. Traces of Mn were only in scutellum globoids. Total P was similar between genotypes for the rest-of-grain fractions, which are 97% of grain mass. The main inositol phosphate was IP6, but a small amount of IP5 was present. Both lpa grain fractions exhibited major reductions in IP6 compared with the wild type and a threefold increase in inorganic P. The concentration of K decreased in both fractions, while Ca increased 25% in the Js-12-LPA rest-of-grain compared with the wild type. The lack of large differences in mineral concentration and distribution between the wild type and Js-12-LPA indicates that there is no direct role of localization of IP6 synthesis in mineral distribution.


2004 ◽  
Vol 14 (2) ◽  
pp. 109-116 ◽  
Author(s):  
John N.A. Lott ◽  
Jessica C. Liu ◽  
Irene Ockenden ◽  
Michael Truax ◽  
John N.A. Lott

Mineral nutrient stores in cereal grains are mainly phytate, a salt of the phosphorus-rich compound phytic acid. Quantitative measures of total phosphorus, phytic acid-phosphorus, potassium, magnesium, calcium, iron, manganese and zinc were obtained for whole grains, embryos and rest-of-grain portions of cv. Kaybonnet rice (wild type) (Oryza sativa L.) and a low phytic acid (lpa1–1) mutant strain with a 45% reduction in phytic acid. P, K and Mg were present in higher amounts than Ca, Mn, Fe and Zn in both grain types. Whole-grain amounts of total P, Ca, Mn and phytic acid-phosphorus were lower in whole lpa1–1 grains than in wild-type grains; K, Mg and Fe amounts were similar, and Zn was higher. Embryos, which comprise 3.5% or less of grain dry weight, were comparatively rich in all measured elements. The lpa1–1 mutation influenced the phytic acid content of the embryo more than that of the aleurone layer. Aleurone-layer cells of wild-type grains had many phosphorus-rich globoids 2μm or larger in diameter, whereas lpa1–1 grains contained more of the smaller globoids. The reduction in globoid size was consistent with the reduction in phytate. Energy-dispersive X-ray analysis of both aleurone-layer cells and sections of globoids in aleurone-layer cells revealed that P, K and Mg were the main mineral nutrient elements present in both grain types; traces of Ca, Mn, Fe or Zn were present. Starchy endosperm cells contained virtually no P, K or Mg, whereas scutellum cells were rich in these elements.


2009 ◽  
Vol 60 (3) ◽  
pp. 967-978 ◽  
Author(s):  
E. Doria ◽  
L. Galleschi ◽  
L. Calucci ◽  
C. Pinzino ◽  
R. Pilu ◽  
...  

Agronomy ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2013
Author(s):  
Muhammad Nawaz ◽  
Sabtain Ishaq ◽  
Hasnain Ishaq ◽  
Naeem Khan ◽  
Naeem Iqbal ◽  
...  

The boron (B) concentration surpasses the plant need in arid and semi-arid regions of the world, resulting in phyto-toxicity. Salicylic acid (SA) is an endogenous signaling molecule responsible for stress tolerance in plants and is a potential candidate for ameliorating B toxicity. In this study, the effects of seed priming with SA (0, 50, 100 and 150 µM for 12 h) on the growth, pigmentation and mineral concentrations of maize (Zea mays L.) grown under B toxicity were investigated. One-week old seedlings were subjected to soil spiked with B (0, 15 and 30 mg kg−1 soil) as boric acid. Elevating concentrations of B reduced the root and shoot length, but these losses were significantly restored in plants raised from seeds primed with 100 µM of SA. The B application decreased the root and shoot fresh/dry biomasses significantly at 30 mg kg−1 soil. The chlorophyll and carotenoid contents decreased with increasing levels of B, while the contents of anthocyanin, H2O2, ascorbic acid (ASA) and glycinebetaine (GB) were enhanced. The root K and Ca contents were significantly increased, while a reduction in the shoot K contents was recorded. The nitrate concentration was significantly higher in the shoot as compared to the root under applied B toxic regimes. However, all of these B toxicity effects were diminished with 100 µM SA applications. The current study outcomes suggested that the exogenously applied SA modulates the response of plants grown under B toxic conditions, and hence could be used as a plant growth regulator to stimulate plant growth and enhance mineral nutrient uptake under B-stressed conditions.


2016 ◽  
Vol 1 (1) ◽  
pp. 54 ◽  
Author(s):  
R. Sozharajan ◽  
S. Natarajan

Maize (Zea mays L.) is the world’s leading edible oil and third largest important cereal. In addition to it is used as food for human consumption as well as food grain for livestock. High concentrations of NaCl in soils account for large decrease in the yield of a large variety of crops all over the globe. The objective of the present study was conducted to evaluate NaCl stress on growth and mineral nutrient composition of maize plants. Maize seeds were grown in plastic pots having fine sand. After 20 days of germination, the plants were subjected to seven different concentrations (Control, 25mM, 50mM, 75mM, 100mM, 125mM and 150mM) of NaCl. Plants were analyzed on 15th day after salt treatment. Factorial experiments in a completely randomized design (CRBD) with three replications were applied. The growth parameters and mineral contents Na, Ca, K and Cl were investigated from saline treated and non saline treated plants. Results indicated that the NaCl stress markedly reduced the shoot and root length fresh and dry masses. Moreover Na+, Cl- content increased with increase in NaCl stress, while Ca2+ and K+ were decreased significantly.


2001 ◽  
Vol 28 (4) ◽  
pp. 307 ◽  
Author(s):  
Adriana Chiappetta ◽  
Walter de Witte ◽  
Milvia L. Racchi ◽  
Maria B. Bitonti ◽  
Henri van Onckelen ◽  
...  

The distribution of cytokinins is strongly altered in seedlings of the shootless ed*41 mutant of maize (Zea mays L.), compared with wild-type. Immunolocalisation of zeatin and analysis of cytokinin levels clearly indicate that these hormones are not present in the shoot apex zone of the mutant. Since an anomalous differentiation of vascular tissues has also been observed in the mutant, a major role of vascular connection in hormone translocation affecting development of the shoot apical meristem is proposed. Immunolocalisation of zeatin was confined to the root cap, cortex and vascular tissues of both mutant and wild-type seedlings suggesting a tissue-specific synthesis of this hormone in the root. A time-course of cytokinin distribution in the wild-type developing shoot provided evidence that the tunica and corpus zones become competent to respond to cytokinins in subsequent periods, very probably in conjunction with photomorphogenesis. On the contrary, this pathway is totally disrupted in the mutant. Taken together, the data point to a relationship between the ed*41 mutation, inadequate vascular connection and disrupted hormone translocation.


Sign in / Sign up

Export Citation Format

Share Document