scholarly journals Protease Activity in the Rhizosphere of Tomato Plants Is Independent from Nitrogen Status

Author(s):  
Hannah Holzgreve ◽  
Manuela Eick ◽  
Christine Stöhr
Author(s):  
Naxin Jiang ◽  
Nguan Soon Tan ◽  
Bow Ho ◽  
Jeak Ling Ding

2013 ◽  
Vol 10 (2) ◽  
pp. 29
Author(s):  
Normah Ismail ◽  
Nur' Ain Mohamad Kharoe

Unripe and ripe bilimbi (Averrhoa bilimbi L.) were ground and the extracted juices were partially purified by ammonium sulfate precipitation at the concentrations of 40 and 60% (w/v). The collected proteases were analysed for pH, temperature stability, storage stability, molecular weight distribution, protein concentration and protein content. Protein content of bilimbi fruit was 0.89 g. Protease activity of both the unripe and ripe fruit were optimum at pH 4 and 40°C when the juice were purified at 40 and 60% ammonium sulfate precipitation. A decreased in protease activity was observed during the seven days of storage at 4°C. Molecular weight distribution indicated that the proteases protein bands fall between IO to 220 kDa. Protein bands were observed at 25, 50 and 160 kDa in both the unripe and ripe bilimbi proteases purified with 40% ammonium sulfate, however, the bands were more intense in those from unripe bilimbi. No protein bands were seen in proteases purified with 60% ammonium sulfate. Protein concentration was higher for proteases extracted with 40% ammonium sulfate at both ripening stages. Thus, purification using 40% ammonium sulfate precipitation could be a successful method to partially purify proteases from bilimbi especially from the unripe stage. 


2015 ◽  
Vol 5 (1) ◽  
pp. 513-522
Author(s):  
Jean-Claude N'ZI ◽  
Lassina FONDIO ◽  
Mako Francois De Paul N’GBESSO ◽  
Andé Hortense DJIDJI ◽  
Christophe KOUAME

Thirty accessions of tomato including twenty eight introduced accessions from The World Vegetable Center-AVRDC and as controls, two commercial varieties Mongal and Calinago, were assessed for agronomic performances at the Experimentation and Production Station of Angud dou of the National Agronomic Research Centre (CNRA) located in the South of Cote d Ivoire. The trial was arranged in a randomized block with three replications. The following parameters were determined at vegetative development stage: plant height at flowering stage, susceptibility of accessions to diseases, day to 50% flowering and day of first harvest, production duration, fruit length, fruit diameter, total number of fruits, number of fruits per plant, potential yield, net yield and fruit damage rate. Results showed that the commercial variety Mongal, with a potential yield of 15.9 and a net yield of 13.1 t ha-1, was the most productive. All the introduced accessions from AVRDC recorded the lowest potential yields from 2.2 to 9.7 t ha-1, and net yields from 1.7 to 8.6 t ha-1. In addition, accessions WVCT8, FMTT847 and WVCT13 were severely infested by bacterial wilt. The reduction of the net yield of tomato accessions resulted in the high fruit damage rates. For the future tomato breeding work, it would be appropriate to introduce into the trials bacterial diseases tolerant varieties. Moreover, some studies could be undertaken to determine the nature of the bacteria involved in the plant wilting and to find out the causal agent of the tomato plants burning at the fructification stage reducing the harvest duration.


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