Assessment of carotenoid and tocopherol level in sweet corn inbred lines during kernel development stages

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1 Indian J. Genet., 75(2): (2015) DOI: / Assessment of carotenoid and tocopherol level in sweet corn inbred lines during kernel development stages Faqiang Feng 1, Qingfeng Wang 1, Jing Zhang, Ruichun Yang and Xiaoqin Li* State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources (Guangzhou), College of Agriculture, South China Agricultural University, Guangzhou, P. R. China (Received: December 2014; Revised: March 2015; Accepted: April 2015) Abstract Among cereals, only maize has amply amount of carotenoids and tocopherols. This study investigated the carotenoids and tocopherols accumulation of the kernels at the 15, 18, 21, 24, 27 and 30 days after pollination using 10 sweet corn inbred lines. The results showed that the contents of carotenoid components from high to low were zeaxanthin, lutein, β-cryptoxanthin, β-carotene and α-carotene. There were no significant differences between 18 and 21days among 5 carotenoid components. The contents of tocopherol components from high to low were γ -tocopherol, α-tocopherol and δ-tocopherol. There were no significant differences between 21, 27 and 30 days among 3 tocopherol components. The variance components of genotypes were higher than that of days after pollination. The content of both carotenoid and tocopherol components reached the peak at 21 and hence, this time was regarded as the optimal harvest period. Key words: Sweet corn, carotenoid, provitamin A, vitamin E, accumulation rate Introduction Many physiological abnormalities will be associated with the lack of vitamin A and vitamin E. Human beings and animals are incapable of carotenoid and tocopherol biosynthesis. Vitamin A and vitamin E are lipid-soluble vitamins that must be acquired regularly from dietary sources. Vitamin A has multiple important functions. It is important for growth and development for the maintenance of the immune system and good vision (Tanumihardjo 2011). Vitamin E is an important antioxidant preventing the propagation of free radicals in tissues, which also plays roles in neurological functions, reproductive functions and immunity functions (Eggermont 2006; Muller 2010; Schneider 2005). The human body can convert carotenoids into vitamin A during the metabolic process (Harjes et al. 2008; Wong et al. 2004). Natural vitamin E includes two distinct groups, tocopherol and tocotrienol according to the saturation of the side chain (Bramley et al. 2000; Rocheford et al. 2002). Both the tocopherols and tocotrienols have four derivatives alpha (α), beta (β), delta (δ) and gamma (γ ), which differ in the number and location of methyl groups (Rocheford et al. 2002). Provitamin A can be found in many fruits and vegetables. In cereals, maize is rich in carotenoids and vitamin E. Its kernels have 5 kinds of natural carotenoid components including α-carotene, β- carotene, β-cryptoxanthin, lutein and zeaxanthin. 95~97% of them are in the endosperm and only about 1% in embryo (Grams et al. 1970). α-carotene, β- carotene and β-cryptoxanthin have the vitamin A activity and lutein and zeaxanthin have no vitamin A activity. The activity of β-carotene is twice of α- carotene and β-cryptoxanthin and the non-vitamin A activity carotenoids, lutein and zeaxanthin, are necessary components for eyes macular areas formation (Sandmann 2001; Handelman 2001). There are 4 kinds of tocopherols (α-tocopherol, β-tocopherol, γ -tocopherol and δ-tocopherol) mainly in the embryo of maize grains (Grams et al. 1970). However, β- tocopherol is negligible because of the extremely low content (Chander et al. 2008). Many papers about the vitamin A and vitamin E of dent corn have been published (Harjes et al. 2008; Wong et al. 2004; Li et *Corresponding author s xiaoqinli2000@aliyun.com 1 Faqiang Feng and Qingfeng Wang contributed equally to this article Published by the Indian Society of Genetics & Plant Breeding, F2, First Floor, NASC Complex, PB#11312, IARI, New Delhi Online management by indianjournals.com

2 May, 2015] Carotenoid and tocopherol level in sweet corn inbred lines 197 al. 2012; Yan et al. 2010; Fu et al. 2013), and the research about sweet corn is less (Feng et al. 2013). So far, dent corn has been the main materials of the research of vitamin A and vitamin in maize. Sweet corn is a type of fresh corn eaten by human directly and its nutrition quality is very important for us. Few researches about the accumulation of vitamin A and vitamin E have been done, so we investigated the changes of carotenoid and tocopherol at kernels different filling stages using 10 sweet corn inbred lines. The aims of this study were to estimate the accumulation rule of carotenoids and tocopherols and study the best harvest time for the micronutrients of sweet corn. Materials and methods Plant materials and field evaluation 10 sweet corn inbred lines (sh 2 sh 2 ) were selected and grown at the South China Agriculture University experimental farm in the autumn of Each genotype was planted 4 rows with ten plants per row and management of the experimental field was the same as productive fields. All plants were selfpollinated and the time of pollination had been recorded. 3 ears per lines at 15, 18, 21, 24, 27 and 30 d after pollination (DAP) had been harvested for carotenoid and tocopherol quantitative analysis, approximately 35g of randomly sampled kernels per line was ground in a FW100 Stein mill for 2 min. Each genotype was quantified with 3 replications. Carotenoid and tocopherol extraction and quantification Carotenoids and tocopherols were simultaneously extracted and measured by high-performance liquid chromatography (HPLC) at National Maize Improvement Center of China using the method described in ref (Chander et al. 2008). Carotenoid and tocopherol content in each sample were simultaneously separated in an YMC carotenoid C 30 column (5 µm, 4.6 mm 250 mm; Waters Chromatography, Milford, MA) connected with a HPLC system of Shimadzu Corporation (Kyoto, Japan) and detected at 450nm and 290nm multi-wavelength using external standards, respectively. Concentration ranges for carotenoid standards, provitamin A (α-carotene, β-carotene, and β-cryptoxanthin) and non-provitamin A carotenoid (lutein and zeaxanthin) were and µg/ml, respectively, whereas ranges of α-tocopherol, δ-tocopherol, and γ -tocopherol were , , and µg/ml, respectively. Total carotenoids and total tocopherols in each sample were computed by adding all the individual carotenoids and tocopherols, respectively. The provitamin A was computed by addingâ-carotene, 1/2 α-carotene and 1/ 2 β-cryptoxanthin together. The carotenoid standard was extracted and purified by National Maize Improvement Center of China and the tocopherol standards were purchased from Sigma (St. Louis, MO). Statistical analysis Analysis was carried out in triplicate for each sample and the results were presented as mean and standard error. Analysis of variance (ANOVA) was used to assess the components of variance and compare the difference among 6 DAPs using the ANOVA procedure of the SAS program (SAS Institute, version 8.0, 1999). Results The variation of carotenoids and tocopherols content The content of carotenoids and tocopherols components at different harvest stages were shown in Table 1 and they reached the maximum value at different harvest time. The carotenoid components, from the highest to the lowest, were zeaxanthin, lutein, β-cryptoxanthin, β-carotene and α-carotene. The lutein content reached the maximum value on 21 days after pollination and ranged from 0.38 to 13.73µg g 1, with the mean of 4.04µg g 1. There were no significant differences among 15, 18 and 21 days after pollination at the 0.01 level and 0.05 level. The zeaxanthin content on 21 days after pollination ranged from 0.66 to 15.41µg g 1 with the mean of 6.60µg g 1. It remains same on the six harvest stages except for 30 days. The β- cryptoxanthin content at 21 days ranged µg g 1 with the mean of 2.19µg g 1. It remains same on the six harvest stages except for 15 days. The content of α-carotene and β-carotene at 21 days after pollination ranged and µg g 1 with the mean of 0.39 and 1.73 µg g 1, respectively. There were no significant differences of α-carotene and β- carotene among six harvest stages. The provitamin A content at 21 days ranged µg g 1 with the mean of 3.03µg g 1 and the content of provitamin A at days was higher than that of provatimin A at 15 days at the 0.05 level. The total carotenoid content at 21 days ranged µg g 1 with the mean of 24.57µg g 1 and the content of the total carotenoid at days was higher than that of the total carotenoid

3 198 Faqiang Feng et al. [Vol. 75, No. 2 Table 1. Comparison of components of carotenoids and tocopherols at different harvest time in 10 sweet corn inbred lines (µg g 1 ) Components Days after pollination Lutein 3.62abAB 3.39abABC 4.04aA 2.84bcABC 2.32cBC 2.18cC Zeaxanthin 5.51abA 6.01abA 6.60aA 6.17abA 6.11abA 5.31bA β-cryptoxanthin 1.62bA 1.93abA 2.19abA 2.21abA 2.41aA 2.23abA α-carotene 0.13aA 0.17aA 0.39aA 0.43aA 0.31aA 0.32aA β-carotene 1.23aA 1.36aA 1.73aA 1.76aA 1.79aA 1.61aA Provitamin A 2.10bA 2.41abA 3.03abA 3.08aA 3.16aA 2.88abA Total carotenoid 11.98bAB 12.85abAB 14.57aA 12.98abAB 12.64abAB 11.33bB δ-tocopherol 2.74aA 2.54aA 2.61aA 2.38aA 1.92aA 1.96aA α-tocopherol 11.32dC 13.20cdBC 15.28abAB 14.09bcAB 15.61abAB 16.64aA γ -tocopherol 33.51cB 41.09abAB 46.36aA 39.24bcAB 42.85abA 45.36abA Total tocopherol 47.57cB 56.83abAB 64.25aA 55.71bAB 60.38abA 63.95aA According to Duncan s multiple rage test (SAS V8.0), means followed by different letters are significantly different at 0.05 (small letters) or 0.01 (capital letters) probability levels at 15 days and 30 days. There were no significant differences between 18 and 21 d among 5 carotenoid components. The content of tocopherol components presented the peak values at different harvest stages. The δ- tocopherol was the minor component and showed no significant differences among 6 harvest stages. The α-tocopherol content on 21 days ranged µg g 1 with the mean of 15.28µg g 1 and the content of 21, 27 and 30 days was higher than the others. γ - tocopherol content on 21 days ranged µg g 1 with the mean of 46.36µg g 1 and the content of 18, 21, 27 and 30 days was higher than the others. The total tocopherol content at 21 days ranged µg g 1 with the mean of 64.25µg g 1. There were no significant differences between 21 days, 27 days and 30 days among 3 tocopherol components. The F values of material-factor and DAP-factor were significant at the 0.01 level or 0.05 level in all of the carotenoid and tocopherol components (Table 2). These results showed that both genotypes factor and DAPs factor affected the content of the carotenoids and tocopherols. The SS (sum of square) of the genotypes were obviously higher than that of DPAs. The minimal mean square and the maximal mean square of DPAs were the α-carotene and total tocopherol with the mean of 0.29 and , respectively. The genotypic mean square of β- carotene, the most active provitamin A component, was only and it is difficult to enhance the content of provitamin A in sweet corn. Discussion Sweet corn is a type of fresh corn harvested and eaten at immature stage. The planting area increased every year in China and its nutrition quality is correlated with the human health. Carotenoids and tocopherols are important micronutrients in sweet corn and it is indispensable to study their accumulation. In this study, the orders of carotenoids content, from high to low, were zeaxanthin, lutein, b-cryptoxanthin, â- carotene and á-carotene, lutein and zeaxanthin were the primary components. The orders of tocopherol content, from high to low, were g-tocopherol, a- tocopherol and d-tocopherol, g-tocopherol and a- tocopherol were the primary components. These results were consistent with the previous studies in dent corn (Chander et al. 2008; Egesel et al. 2003; Goffman et al. 2001) and sweet corn (Feng et al. 2013). In this study, both genotypes and DAPs affected the content of the carotenoids and tocopherols. The SS of the genotypes were obviously higher than that of DPAs, indicating that the genotypes had a major influence on the biosynthesis of carotenoids and tocopherols. The dry mass accumulation rate in dent corn reached the maximum value during days after pollination and then it slowed down (Jiang et al. 2007). The same accumulation changes in most carotenoid and tocopherol components were observed

4 May, 2015] Carotenoid and tocopherol level in sweet corn inbred lines 199 Table 2. Two-way ANOVA analysis of carotenoids and tocopherols in 10 lines (µg g 1 ) Component Treatments SS Mean square F P Lutein materials ** < DAPs ** < Zeaxanthin materials ** < DAPs * β-cryptoxanthin materials ** < DAPs ** α-carotene materials ** <0.001 DAPs ** µ-carotene materials ** <0.001 DAPs ** Provitamin A materials ** <0.001 DAPs ** Total carotene materials ** <0.001 DAPs ** α-tocopherol materials ** <0.001 DAPs ** <0.001 δ-tocopherol materials ** <0.001 DAPs * γ -tocopherol materials ** <0.001 DAPs ** <0.001 Total tocopherol materials ** <0.001 DAPs ** <0.001 * and **indicate the significant F values at 0.05 and 0.01 level, respectively in this research and it was also similar with the research of Kurilich and Juvik (1999). It is very worthy of studying the accumulation of carotenoids and tocopherols to identify the best harvest time in sweet corn. In general, the best harvest time was regarded as the kernels with 70% water and it could be confirmed by the effective accumulated temperature and days after pollination (Lian et al. 1989). Khanduri et al. (2011) regarded 20 days after pollination as the best harvest time after studying the sugar concentration at 20, 24 and 28 days after pollination. These researches about the best harvest time involved in the sugar concentration and eaten quality, but ignored the micronutrients. In this study, the content of carotenoids and tocopherols reached the peak values at 21 days after pollination, so this special time could be regarded as the best harvest time in sweet corn. This result provided the theoretical basis for the best harvest time for the micronutrient accumulation in sweet corn. Acknowledgments This study was supported by the Nature Science Foundation of China (Project No ). National Maize Improvement Center of China, China Agricultural University is gratefully acknowledged. References Bramley P. M., Elmadfa I., Kafatos A., Kelly F. J., Manios Y., Roxborough H. E., Schuch W., Sheehy P. and Wagner K Critical reviews produced within the EU Concerted Action Nutritional enhancement of plant-based food in European trade Neodiet - Vitamin E. Sci. Food Agri., 80: Chander S., Guo Y., Yang X., Yan J., Zhang Y., Song T. and Li J Genetic dissection of tocopherol content and composition in maize grain using quantitative trait loci analysis and the candidate gene approach. Mol. Breeding., 22: Chander S., Meng Y., Zhang Y., Yan J. and Li J Comparison of nutritional traits variability in selected eighty-seven inbreds from Chinese maize Zea mays L. germplasm. J. Agric. Food Chem., 56: Eggermont E Recent advances in vitamin E metabolism and deficiency. Eur. J. Pediatr., 165: Egesel C. O., Wong J. C., Lambert R. J. and Rocheford T. R Combining ability of maize inbreds for

5 200 Faqiang Feng et al. [Vol. 75, No. 2 carotenoids and tocopherols. Crop Sci., 43: Feng F., Deng F., Zhou P., Yan J., Wang Q., Yang R. and Li X QTL mapping for the tocopherols at milk stage of kernel development in sweet corn. Euphytica, 193: Fu Z., Chai Y., Zhou Y., Yang X., Warburton M., Xu S., Cai Y., Zhang D., Li J. and Yan J Natural variation in the sequence of PSY1 and frequency of favorable polymorphisms among tropical and temperate maize germplasm. Theor. Appl. Genet., 126: Goffman F. D. and Boehme T Relationship between fatty acid profile and vitamin E content in maize hybrids Zea mays L. J. Agr. Food Chem., 49: Grams G. W., Blessin C. W. and Inglett G. E Distribution of tocopherols within the corn kernel. J. Am. Oil. Chem. Soc., 479: Handelman G. J The evolving role of carotenoids in human biochemistry. Nutrition, 1710: Harjes C. E., Rocheford T. R., Bai L., Brutnell T. P., Kandianis C. B., Sowinski S. G., Stapleton A. E., Vallabhaneni R., Williams M., Wurtzel E. T., Yan J. and Buckler E. S Natural Genetic Variation in Lycopene Epsilon Cyclase Tapped for Maize Biofortification. Science, 319: Jiang Y. L. and Zhang F. L study on development of summer maize kernel. ACTA Agriculturae Boreali- Sinica, 22: Khanduri A., Hossain F., Lakhera P. C. and Prasanna B. M Effect of harvest time on kernel sugar concentration in sweet corn. Indian J. Genet. Pl. Br., 71: Kurilich A. C. and Juvik J. A Quantification of Carotenoid and Tocopherol Antioxidants in Zea mays. J. Agric. Food Chem., 47: Li Q., Yang X., Xu S., Cai Y., Zhang D., Han Y., Li L., Zhang Z., Gao S., Li J. and Yan J Genome-Wide Association Studies Identified Three Independent Polymorphisms Associated with α-tocopherol Content in Maize Kernels. PLOS ONE, 7: e Lian H. Q., Song T. M., Zhang L. P. and Xu G. Q he effect of different genotypes, harvest time, storage temperature and period on sweet corn quality. ACTA Agriculturae Universitatis Pekinensis, 15: Muller D Vitamin E and neurological function. Mol. Nutr. Food Res., 545: Rocheford T. R., Wong J. C., Egesel C. O. and Lambert R. J Enhancement of Vitamin E Levels in Corn. J. Amer. Coll. Nutr., 21: Sandmann G Genetic manipulation of carotenoid biosynthesis, strategies, problems and achievements. Trends Plant Sci., 61: Schneider C Chemistry and biology of vitamin E. Mol. Nutr. Food Res., 491: Tanumihardjo S. A Vitamin A, biomarkers of nutrition for development. Am. J. Clin. Nutr., 942: 658S-65S. Wong J. C., Lambert R. J., Wurtzel E. T. and Rocheford T. R QTL and candidate genes phytoene synthase and β-carotene desaturase associated with the accumulation of carotenoids in maize. Theor. Appl. Genet., 108: Yan J., Kandianis C. B., Harjes C. E., Bai L., Kim E., Yang X., Skinner D. J., Fu Z., Mitchell S., Li Q., Fernandez M. G. S., Zaharieva M., Babu R., Fu Y., Palacios N., Li J., DellaPenna D., Brutnell T., Buckler E. S., Warburton M. L. and Rocheford T Rare genetic variation at Zea mays crtrb1 increases β- carotene in maize grain. Nat. Genet., 42:

Characterization of maize population for pro-vitamin A carotenoids using TLC

[Vol. 13 (2), May - August 2015] International Journal of Basic and Applied Agricultural Research 181 Characterization of maize population for pro-vitamin A carotenoids using TLC MAHAK TUFCHI 1, RASHMI