Purple acid phosphatase (PAP; EC 3.1.3.2) enzymes are metallophosphoesterases that hydrolysis pho... more Purple acid phosphatase (PAP; EC 3.1.3.2) enzymes are metallophosphoesterases that hydrolysis phosphate ester bonds in a wide range of substrates. Twenty-nine PAP-encoding loci have been identified in the Arabidopsis genome, many of which have multiple transcript variants expressed in response to diverse environmental conditions. Having analyzed T-DNA insertion mutants, we have provided strong pieces of evidence that AtPAP9 locus encodes at least two types of transcripts, designated as AtPAP9-1 and AtPAP9-2. These transcript variants expressed distinctly during the course of growth in medium containing sufficient phosphate or none. Further histochemical analysis by the use of AtPAP9-1 promoter fused to β-glucuronidase reporter gene indicated the expression of this gene is regulated in a tissue-specific manner. AtPAP9-1 was highly expressed in stipule and vascular tissue, particularly in response to fungal infection. Subcellular localization of AtPAP9-1:green fluorescent fusion protein showed that it must be involved in plasma membrane and cell wall adhesion.
To prevent enzymatic browning, applying a polyphenol oxidase (PPO) inhibitor is more desirable, e... more To prevent enzymatic browning, applying a polyphenol oxidase (PPO) inhibitor is more desirable, especially when the freshness of the product matters. Most of the inhibition studies were done on mushroom tyrosinase (MT) while the literature indicates that MT and PPO of Solanum tuberosum (PPOsol ) respond differently to the same modulator despite their similar active sites. This research was conducted to deepen our knowledge about PPOsol and introduce a more specific inhibitor for this enzyme to be used in controlling the enzymatic browning of potatoes. A modified procedure was developed for PPOsol purification. The enzyme was subjected to some essential physicochemical and kinetics studies. In parallel to the comparable physicochemical properties, homology modeling revealed high structural similarity between Solanum lycopersicum PPO (PPOsly ) and PPOsol except for their active site pockets. Accordingly, PPOsol showed 5.1- and 34-fold higher affinity toward chlorogenic acid compared with two PPOsly isozymes. Alike PPOsly , PPOsol showed monophenolase activity but it was inactive toward L-tyrosine and p-coumaric acid. Based on structural criteria, phthalic acid, cinnamic acid, ferulic acid, and vanillin were selected and thoroughly examined for inhibition of the catecholase activity of PPOsol . Although all these substances inhibited PPOsol in mixed-inhibition mode, the results were strongly in favor of vanillin with IC50 < 1.37 mM and Ki < 1.2 mM. PRACTICAL APPLICATIONS: There are subtle structural differences in the active site pockets of polyphenol oxidase (PPOs) of various fruits, vegetables, and crops. Consequently, to introduce an efficient inhibitor for hindering enzymatic browning of crop products, it is essential to have detailed knowledge about the structure and activity of its PPO as the main player of this undesirable phenomenon. Results of this study not only shed light on the physicochemical properties of PPOsol but can also be used in making various formulations for safe controlling enzymatic browning of potatoes, especially fresh-cut and minimally processed products, and similar crops products during postharvest and the processes of products preparations.
Amongst the transcription factor groups, the AP2/ERF (Apetala2/Ethylene Response Factor) superfam... more Amongst the transcription factor groups, the AP2/ERF (Apetala2/Ethylene Response Factor) superfamily is one of the main groups in plants and plays an essential role in tolerating abiotic and biotic stresses. The AP2/ERF superfamily consists of ERF, AP2, RAV, and Soloist families based on the AP2 domain number. The RAV (Related to ABI3/VP1) family members have been revealed to be stimulate by a number of biotic and abiotic environmental incentives; including pathogen infection, salicylic acid, osmotic stress, cold, high salinity, wounding, and exogenous hormone application. However, limited data are available on the contributions of RAV transcription factors in wheat (Triticum aestivum L.). In the present study, a total of 26 RAV genes were identified in wheat from a genome-wide search against the latest wheat genome data. Phylogenetic and sequence alignment analyses divided the wheat RAV genes into 4 clusters, I, II, III and IV. Chromosomal distribution, gene structure and motif composition were subsequently investigated. The 26 TaRAV genes were unevenly distributed on 21 chromosomes. After cloning and sequencing of 7 TaRAVs candidate genes the expression levels of two TaRAVs, TaRAV4 and TaRAV5, were validated through qPCR analyses in two salt-tolerant Iranian landraces of wheat. Our results showed that the TaRAV4 and TaRAV5 were co-expressed in wheat tissues and were highly correlated to salt tolerance indices such as the K+/Na+ ratio. Protein interaction revealed that the TaRAV4 and TaRAV5 were related to vital proteins such as PK4 and PP2C, and MYB and Zinc finger transcription factors, and Gigantea proteins. This study improved our knowledge of the RAV gene family function in wheat and the probable role of RAVs in salt tolerance mechanisms to improve crop production under changing environments. Also, the two relatively salt-tolerant landraces of wheat that were examined in this study could be suitable candidates for future breeding studies.
ABSTRACT Zinc (Zn) has a vast number of functions in plant metabolism, the lack of which had dram... more ABSTRACT Zinc (Zn) has a vast number of functions in plant metabolism, the lack of which had dramatic effects on growth and yield of plants. Plants have morphological and biochemical responses to enhance mineral solubility in the soil and facilitate uptake, such as root plasticity, secretion processes and symbioses. Root architecture modification is an important plant response to nutrient availability. The aim of this study was to identify root morphological reactions to Zn efficiency in Iranian bread wheat genotypes. Soil and solution cultures were used to survey Zn efficiency. In soil culture, six and seven genotypes with high and low Zn contents were selected among 110 Iranian bread wheat genotypes, respectively. The solution culture experiments were set up in a completely randomized block design and plants fed with Johnson’s grass solution. All traits were assessed at 30 and 60 DAPs (days after planting). Our results showed a significant difference between two groups of efficient and inefficient genotypes only at 60 DAP, and Zn-efficient genotypes showed 1.63-, 1.50-, 1.69- and 1.92-fold increases in root diameter, surface area density, shoot and root dry weight, respectively, compared to inefficient genotypes. In contrast, Zn-inefficient genotypes had 1.20- and 2.62-fold more root length and fineness, respectively, than efficient genotypes. The positive significant correlations were observed between shoot and Zn uptake as well as root dry weight and Zn uptake at both stages. Furthermore, shoot and root dry weight showed a significant correlation with root fineness, diameter and surface area density at both stages. The path analysis showed indirect effects on Zn uptake through root traits. Our results showed that roots have a major role in Zn efficiency. Therefore, the better growth and greater Zn uptake in efficient genotypes, compared to inefficient ones, can be attributed to greater root diameter and surface area density, and lower root fineness in these genotypes.
Clustering of genes using their expression data has been a major topic in recent years. A large a... more Clustering of genes using their expression data has been a major topic in recent years. A large amount of gene expression data even in time series are obtained by microarray technology. Finding gene clusters with similar functions and interconnecting genes by networks has an important role in mining biological gene functional analysis. In this paper, two phase functional clustering has
... OF HYOSCYAMUS NIGER L. BY POLYMRASE CHAIN REACTION HASSAN EBRAHIMZADEH, AFSANEH TEIMOORI and ... more ... OF HYOSCYAMUS NIGER L. BY POLYMRASE CHAIN REACTION HASSAN EBRAHIMZADEH, AFSANEH TEIMOORI and TAHMINEH LOHRASEBI Department of ... alkaloids such as hyoscyamine and scopolamine are widely used as anticholinergic \лх (лглх :amir\í=> noe ...
Purple acid phosphatase (PAP; EC 3.1.3.2) enzymes are metallophosphoesterases that hydrolysis pho... more Purple acid phosphatase (PAP; EC 3.1.3.2) enzymes are metallophosphoesterases that hydrolysis phosphate ester bonds in a wide range of substrates. Twenty-nine PAP-encoding loci have been identified in the Arabidopsis genome, many of which have multiple transcript variants expressed in response to diverse environmental conditions. Having analyzed T-DNA insertion mutants, we have provided strong pieces of evidence that AtPAP9 locus encodes at least two types of transcripts, designated as AtPAP9-1 and AtPAP9-2. These transcript variants expressed distinctly during the course of growth in medium containing sufficient phosphate or none. Further histochemical analysis by the use of AtPAP9-1 promoter fused to β-glucuronidase reporter gene indicated the expression of this gene is regulated in a tissue-specific manner. AtPAP9-1 was highly expressed in stipule and vascular tissue, particularly in response to fungal infection. Subcellular localization of AtPAP9-1:green fluorescent fusion protein showed that it must be involved in plasma membrane and cell wall adhesion.
To prevent enzymatic browning, applying a polyphenol oxidase (PPO) inhibitor is more desirable, e... more To prevent enzymatic browning, applying a polyphenol oxidase (PPO) inhibitor is more desirable, especially when the freshness of the product matters. Most of the inhibition studies were done on mushroom tyrosinase (MT) while the literature indicates that MT and PPO of Solanum tuberosum (PPOsol ) respond differently to the same modulator despite their similar active sites. This research was conducted to deepen our knowledge about PPOsol and introduce a more specific inhibitor for this enzyme to be used in controlling the enzymatic browning of potatoes. A modified procedure was developed for PPOsol purification. The enzyme was subjected to some essential physicochemical and kinetics studies. In parallel to the comparable physicochemical properties, homology modeling revealed high structural similarity between Solanum lycopersicum PPO (PPOsly ) and PPOsol except for their active site pockets. Accordingly, PPOsol showed 5.1- and 34-fold higher affinity toward chlorogenic acid compared with two PPOsly isozymes. Alike PPOsly , PPOsol showed monophenolase activity but it was inactive toward L-tyrosine and p-coumaric acid. Based on structural criteria, phthalic acid, cinnamic acid, ferulic acid, and vanillin were selected and thoroughly examined for inhibition of the catecholase activity of PPOsol . Although all these substances inhibited PPOsol in mixed-inhibition mode, the results were strongly in favor of vanillin with IC50 < 1.37 mM and Ki < 1.2 mM. PRACTICAL APPLICATIONS: There are subtle structural differences in the active site pockets of polyphenol oxidase (PPOs) of various fruits, vegetables, and crops. Consequently, to introduce an efficient inhibitor for hindering enzymatic browning of crop products, it is essential to have detailed knowledge about the structure and activity of its PPO as the main player of this undesirable phenomenon. Results of this study not only shed light on the physicochemical properties of PPOsol but can also be used in making various formulations for safe controlling enzymatic browning of potatoes, especially fresh-cut and minimally processed products, and similar crops products during postharvest and the processes of products preparations.
Amongst the transcription factor groups, the AP2/ERF (Apetala2/Ethylene Response Factor) superfam... more Amongst the transcription factor groups, the AP2/ERF (Apetala2/Ethylene Response Factor) superfamily is one of the main groups in plants and plays an essential role in tolerating abiotic and biotic stresses. The AP2/ERF superfamily consists of ERF, AP2, RAV, and Soloist families based on the AP2 domain number. The RAV (Related to ABI3/VP1) family members have been revealed to be stimulate by a number of biotic and abiotic environmental incentives; including pathogen infection, salicylic acid, osmotic stress, cold, high salinity, wounding, and exogenous hormone application. However, limited data are available on the contributions of RAV transcription factors in wheat (Triticum aestivum L.). In the present study, a total of 26 RAV genes were identified in wheat from a genome-wide search against the latest wheat genome data. Phylogenetic and sequence alignment analyses divided the wheat RAV genes into 4 clusters, I, II, III and IV. Chromosomal distribution, gene structure and motif composition were subsequently investigated. The 26 TaRAV genes were unevenly distributed on 21 chromosomes. After cloning and sequencing of 7 TaRAVs candidate genes the expression levels of two TaRAVs, TaRAV4 and TaRAV5, were validated through qPCR analyses in two salt-tolerant Iranian landraces of wheat. Our results showed that the TaRAV4 and TaRAV5 were co-expressed in wheat tissues and were highly correlated to salt tolerance indices such as the K+/Na+ ratio. Protein interaction revealed that the TaRAV4 and TaRAV5 were related to vital proteins such as PK4 and PP2C, and MYB and Zinc finger transcription factors, and Gigantea proteins. This study improved our knowledge of the RAV gene family function in wheat and the probable role of RAVs in salt tolerance mechanisms to improve crop production under changing environments. Also, the two relatively salt-tolerant landraces of wheat that were examined in this study could be suitable candidates for future breeding studies.
ABSTRACT Zinc (Zn) has a vast number of functions in plant metabolism, the lack of which had dram... more ABSTRACT Zinc (Zn) has a vast number of functions in plant metabolism, the lack of which had dramatic effects on growth and yield of plants. Plants have morphological and biochemical responses to enhance mineral solubility in the soil and facilitate uptake, such as root plasticity, secretion processes and symbioses. Root architecture modification is an important plant response to nutrient availability. The aim of this study was to identify root morphological reactions to Zn efficiency in Iranian bread wheat genotypes. Soil and solution cultures were used to survey Zn efficiency. In soil culture, six and seven genotypes with high and low Zn contents were selected among 110 Iranian bread wheat genotypes, respectively. The solution culture experiments were set up in a completely randomized block design and plants fed with Johnson’s grass solution. All traits were assessed at 30 and 60 DAPs (days after planting). Our results showed a significant difference between two groups of efficient and inefficient genotypes only at 60 DAP, and Zn-efficient genotypes showed 1.63-, 1.50-, 1.69- and 1.92-fold increases in root diameter, surface area density, shoot and root dry weight, respectively, compared to inefficient genotypes. In contrast, Zn-inefficient genotypes had 1.20- and 2.62-fold more root length and fineness, respectively, than efficient genotypes. The positive significant correlations were observed between shoot and Zn uptake as well as root dry weight and Zn uptake at both stages. Furthermore, shoot and root dry weight showed a significant correlation with root fineness, diameter and surface area density at both stages. The path analysis showed indirect effects on Zn uptake through root traits. Our results showed that roots have a major role in Zn efficiency. Therefore, the better growth and greater Zn uptake in efficient genotypes, compared to inefficient ones, can be attributed to greater root diameter and surface area density, and lower root fineness in these genotypes.
Clustering of genes using their expression data has been a major topic in recent years. A large a... more Clustering of genes using their expression data has been a major topic in recent years. A large amount of gene expression data even in time series are obtained by microarray technology. Finding gene clusters with similar functions and interconnecting genes by networks has an important role in mining biological gene functional analysis. In this paper, two phase functional clustering has
... OF HYOSCYAMUS NIGER L. BY POLYMRASE CHAIN REACTION HASSAN EBRAHIMZADEH, AFSANEH TEIMOORI and ... more ... OF HYOSCYAMUS NIGER L. BY POLYMRASE CHAIN REACTION HASSAN EBRAHIMZADEH, AFSANEH TEIMOORI and TAHMINEH LOHRASEBI Department of ... alkaloids such as hyoscyamine and scopolamine are widely used as anticholinergic \лх (лглх :amir\í=> noe ...
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