Authors:X.L. Jiang, G.F. Chen, X.J. Li, G. Li, Z.G. Ru, and J.C. Tian
This study aimed to clarify the genetic mechanisms behind wheat flour color. Flour colorrelated traits (L*, a*, and b*) and polyphenol oxidase (PPO) activity are important parameters that influence the end-use quality of wheat. Dissecting the genetic bases and exploring important chromosomal loci of these traits are extremely important for improving wheat quality. The diverse panel of 205 elite wheat varieties (lines) was genotyped using a highdensity Illumina iSelect 90K single-nucleotide polymorphisms (SNPs) assay to disclose the genetic mechanism of flour color-related traits and PPO activity. In 2 different environments and their mean values (MV), 28, 30, 24, and 12 marker-trait associations (MTAs) were identified for L*, a*, b* traits, and PPO activity, respectively. A single locus could explain from 5.52% to 20.01% of the phenotypic variation for all analyzed traits. Among them, 5 highly significant SNPs (P ≤ 0.0001), 11 stable SNPs (detected in all environments) and 25 multitrait MTAs were identified. Especially, BS00000020_51 showed pleiotropic effects on L*, a*, and b*, and was detected in all environments with the highest phenotypic contribution rates. Furthermore, this SNP was also found to be co-associated with wheat grain hardness, ash content, and pasting temperature of starch in previous studies. The identification of these significantly associated SNPs is helpful in revealing the genetic mechanisms of wheat colorrelated traits, and also provides a reference for follow-up molecular marker-assisted selection in wheat breeding.
Authors:K. Körösi, F. Virányi, B. Barna, and R. Bán
synthesis of wound-inducible tomato leaf polyphenoloxidase via the octadecanoid defense signaling pathway . Plant Biol. 92 , 407 – 411 .
Desmond , O. J. , Edgar , C. I. , Manners , J. M. , Maclean , D. J. , Schenk , P. M. and Kazan , K
Authors:I. Szedljak, K. Szántai-Kőhegyi, M. Tóth, and B. Bernhardt
Millet has attracted a great deal of interest due to its valuable agricultural, nutritional, and functional properties. In this study the aim was the investigation of millet usability in dry pasta products. Chemical, enzymological, and sensory parameters were measured and monitored in Triticum aestivum, Triticum durum, and millet containing pasta products during a 12-month-long storage period. According to our results, during the storage, millet had a strong effect on different parameters: because of increased acid value, the shelf life was reduced, and millet significantly influenced the pH value and the water soluble polyphenol content. The highest scores were measured in T. durum and T. durum-millet pasta samples in the sensory test, while the T. aestivum-millet mixture pasta got the lowest scores. Also in our experiment we tested how the drying temperature modifies polyphenol oxidase enzyme (PPO) activity right after drying and during storage. The samples containing millet flour had higher PPO activity in all cases after drying, while pasta made with T. durum had the lowest PPO activity. Our results showed that drying temperature has a significant impact on PPO activity.
Authors:Roghieh Hajiboland, Sara Bahrami-Rad, and Soodabeh Bastani
Modification in the metabolism of phenolic compounds under boron (B) deficiency conditions was studied in tea plants. Plants were grown from seed, treated with low B in hydroponic medium under environmentally controlled conditions for six weeks. Dry matter production and B content of plants were significantly declined under B deficiency conditions. Boron starvation resulted in rising phenylalanine ammonia lyase activity in the young leaves and declining polyphenol oxidase activity in the roots. Soluble phenolics fraction was increased up to 3.4-fold in the young leaves while did not influence by B nutrition in the old leaves and roots. Cell wall (CW) bound phenolics and lignin content was lower in B-deficient plants compared with B-sufficient ones. Boron deficiency increased significantly activity of soluble peroxidase (POD) only in the leaves. Activity of ionically bound POD was decreased in the old leaf and roots while it increased in the young leaves upon B deprivation. Activity of covalently bound POD decreased in the roots and leaves of different age in low B plants. Our results suggested that tea plant is highly tolerant species to B deficiency and CW tightening and accumulation of oxidized phenolics are not mechanisms for growth inhibition under B deficiency conditions.
Authors:I. Szedljak, K. Szántainé Kőhegyi, and M. Tóth
Millet (Panicum miliaceum L.) is more resistant to climatic and soil conditions but the yields are lower than in wheat (Triticum aestivum L.), therefore its cultivation was given up for decades in Hungary. Millet is a suitable raw material for the production of pasta products without using eggs and it has other advantageous physiological effects, therefore its cultivation in Hungary is expected again. Millet is a gluten free cereal so it is not able to create viscoelastic protein network. During the biochemical studies the activity of enzymes (peroxidase, polyphenol oxidase) influencing the colour of the flour, flour mixtures (T. aestivum L., Triticum durum L., P. miliaceum L.), and pasta products were examined. Oxidoreductases in wheat flour have always been of interest to cereal chemists. The effects of peroxidase (EC 220.127.116.11) (POX) are much less thoroughly documented, although they are reported to have a relatively high level of activity in different flours. These days there are also insufficient research data on how the millet in dry pasta modifies the enzyme activity and the storage stability and shelf life of dry pasta products.