Identification and partial purification of thermally stable peroxidase isoenzymes from seedlings of Vigna sp. (V) landrace Vn

Several soluble peroxidase isoenzymes are expressed in a landrace of Vigna sp. cultivated in the north of Cameroon (landrace called Vn in previous study) during seed germination. There are at least two cathodic peroxidases and eight major anodic peroxidases as shown by their electrophoretic migration at pH 7.4 under native conditions. These isoperoxidases are more expressed in roots than in shoots. They have different thermal stability, so that heat inactivation kinetics of crude peroxidase extracts from roots do not fit the first-order model. The slow and intermediate migrating groups of anodic isoperoxidases retains a substantial activity after ten minutes of incubation at 80°C and 85°C. An anodic isoperoxidase (named A6 in this study) shows in addition to this great thermal stability, a high activity in seedlings and is expressed both in roots and shoots. The combination of those characteristics makes this isoperoxidase a potential candidate for biotechnological applications. Three major anodic isoperoxidases, of which A6 and another thermostable isoperoxidase, were successfully separated from each other by ion exchange chromatography on DEAE-cellulose, after precipitation of total proteins by ice-cold acetone. This offers the prospect of being able to characterize these isoperoxidases individually in future studies.

Peroxidase isoenzymes from seedlings of VIGNA sp (V) landrace Vn: distribution and thermal stability

Several soluble peroxidase isoenzymes are expressed in a landrace of Vigna sp cultivated in the north of Cameroon (landrace called Vn in previous study) during seed germination. There are at least two cathodic peroxidases and eight major anodic peroxidases as shown by their electrophoretic migration at pH 7.4 under native conditions. These isoperoxidases are more expressed in radicles than in shoots. They have different thermal stability, so that heat inactivation kinetics of crude peroxidase extracts from radicles does not fit the first-order model. One major anodic isoperoxidase of the slow migrating group and at least two others anodic isoperoxidases of the The slow and intermediate migrating groups of anodic isoperoxidasesanodic isoperoxidases are stable for ten minutes of incubation at 80°C and 85°C. The major anodic isoperoxidase of the The less anodic slow migrating groupisoperoxidase (named A6 in this study) shows in addition to this great thermal stability, a high activity during germination and is expressed both in radicles and shoots in large amounts. The combination of those characteristics makes thisthat isoperoxidase a a potential candidate for biotechnological applications.

Flavonoids and isoenzymes as chemotaxonomic markers in Cleome L.(Cleomaceae Bercht. & J.Presl)

These studies were conducted on the twoflavonoid compounds of quercetin and kaempferol in addition electrophoretic studies of esterase and peroxidase isoenzymes by SDS-polyacrylamide gel electrophoresisfor five <em>Cleome</em>L. species. Extraction of these flavonoids was carried out using 90% ethanol and 85% methanol. Identification and quantification of quercetin and kaempferol was done using thin Layer chromatography (TLC) and further augmented using high performance liquid chromatography (HPLC) and then isolated,purified and identified using melting point (M.P.) and infrared spectroscopy (IR).eightquercetinand seven kaempferol compounds are isolated and identified with different percentages. Electrophoretic patterns of two isoenzymes ofesterases (Est) and peroxidases (Prx) considered a good taxonomicmarker techniques. A total 45 esterase and peroxidase bands obtained scanning the gels. The highest combined esterase and peroxidase bands (13 bands) are found in <em>C.scaposa</em> DCwhereasthe lowest seven bands are recorded in <em>C. paradoxa</em> B.BR.35 obtained data of two flavonoid compounds and two isoenzymeswere subjected to numerical analysis which separated the studied species into two groups, the first has <em>C.gynandra</em>. and <em>C. viscosa </em>L., the second group included three species of <em>C. scaposa </em>DC<em>, C. brachycarpa </em>. and<em> C. paradoxa</em>.

Peroxidase isoenzymes in germinating barley seeds and in seminal roots

Roots and germinating seeds of summer barley of the cv. Alsa, Antałek, Cebeco 7161, Lubuski, Skrzeszowicki and Union were found to differ in the number of peroxidase isoenzymes. In the germinating seeds from 5 to 8 isoenzymes were found whereas in the two-week-old roots – from 10 to 14 isoenzymes. Four isoenzymes in germinating seeds and eight isoenzymes in seminal roots appeared in all the cultivars tested. The cultivars differed also in the relative activity of the isoenzymes in the tested organs.

Physiological performance of rice seeds treated with thiamethoxam or rhizobacteria under different temperatures

This study aimed to evaluate, at 15, 20 and 25 ºC, the physiological potential and enzyme activity of seedlings from six samples of rice seeds stored for one year and treated with growth-promoting rhizobacteria (Pseudomonas synxantha) and the bioactivator thiametoxam. The following were evaluated: seed germination, first germination count, root protrusion speed index, emergence percentage and emergence speed index, shoot and root length and enzyme activity (esterases, α-amylase and peroxidases) at 15, 20 and 25 ºC. In these conditions, thiametoxam and the rhizobacteria P. synxantha (DFs 185) improved the physiological performance of rice seeds with physiological qualities at low temperatures (20 and 15 ºC) and did not change the expression of the esterase and peroxidase isoenzymes. The rhizobacteria P. synxantha (DFs 185) increased the expression of the enzyme α-amylase at low temperatures.