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[EN] Selection and improvement of crops subjected to salinity constitutes an urgent need for increasing agricultural and food production in order to feed the growing human population. The aim of the present study is to evaluate the role of salicylic acid (SA) application in mitigating the adverse effects of salinity on faba bean (Vicia faba L.) at the physiological and molecular levels. Fort this purpose, two faba bean genotypes were subjected to various concentrations of NaCl and salicylic acid in a full factorial design. After that, growth, water status, gas exchanges, photosynthesis parameters, ions homeostasis and antioxidant enzymes activities were evaluated. The obtained results demonstrated that salinity induced several limitations in plants growth and physiological attributes. In response, salt stressed faba bean plants improved water status and enhanced antioxidant enzymatic activities. Remarkably, salt-tolerance of both genotypes was significantly improved by salicylic acid application which allowed the maintenance of cell membrane and photosynthetic process, restoring of ion homeostasis and the diminution of oxidative damages. Overall, the difference between genotypes is rather quantitative than qualitative even if the genotype Aguadulce displayed better growth, physiological and molecular response under salt stress than the genotype Histal. Besides, the beneficial effects of salicylic acid vary according to its concentration, the tested genotype and the studied parameter; the genotype Aguadulce performs better under the treatment with 0.5 mM SA while the genotype Histal manifests greater behaviour under the treatment with 1 mM SA. Therefore, salicylic acid can be considered as potential growth regulator to improve the salt response of faba bean. The application of salicylic acid would provide a practical basis for wide cultivation of faba bean in marginal and wastelands under-cultivated and might propose an effective ecological and economical alternative

[EN] Selection and improvement of crops subjected to salinity constitutes an urgent need for increasing agricultural and food production in order to feed the growing human population. The aim of the present study is to evaluate the role of salicylic acid (SA) application in mitigating the adverse effects of salinity on faba bean (Vicia faba L.) at the physiological and molecular levels. Fort this purpose, two faba bean genotypes were subjected to various concentrations of NaCl and salicylic acid in a full factorial design. After that, growth, water status, gas exchanges, photosynthesis parameters, ions homeostasis and antioxidant enzymes activities were evaluated. The obtained results demonstrated that salinity induced several limitations in plants growth and physiological attributes. In response, salt stressed faba bean plants improved water status and enhanced antioxidant enzymatic activities. Remarkably, salt-tolerance of both genotypes was significantly improved by salicylic acid application which allowed the maintenance of cell membrane and photosynthetic process, restoring of ion homeostasis and the diminution of oxidative damages. Overall, the difference between genotypes is rather quantitative than qualitative even if the genotype Aguadulce displayed better growth, physiological and molecular response under salt stress than the genotype Histal. Besides, the beneficial effects of salicylic acid vary according to its concentration, the tested genotype and the studied parameter; the genotype Aguadulce performs better under the treatment with 0.5 mM SA while the genotype Histal manifests greater behaviour under the treatment with 1 mM SA. Therefore, salicylic acid can be considered as potential growth regulator to improve the salt response of faba bean. The application of salicylic acid would provide a practical basis for wide cultivation of faba bean in marginal and wastelands under-cultivated and might propose an effective ecological and economical alternative

This article provides a meta-analysis of quantitative data available in literature regarding the relation between termite numbers and the volume of their mounds for 24 species belonging to 13 genera. The leading question behind this analysis is: "how do the respiratory gas exchanges regulate the size of termite mounds?" This question is answered through the analysis of the log-log regression between the volume of the mound and the number of inhabitants. The most confident data support the hypothesis of a respiratory regulation that can be achieved through a relation between the termite numbers and (1) the volume of their mounds (slope of the regression near 1, Noditermes), (2) the surface of the outer walls of their mounds (slope of the regression near 0.67, Termitinae and Nasutitermes) or (3) a compromise between the surface of the outer walls of their mounds and some linear structures of their nests (slope of the regression between 0.67 and 0.33, Trinervitermes and Macrotermes). The way this is achieved is linked with the architecture of the mound. A confident relation was found between the number of individuals and the epigeal volume of their mounds for 18 species for which the most reliable data were provided. Three more accurate models are proposed for estimating the termite population based on the nest material and architecture and on the size of the termites. © International Union for the Study of Social Insects (IUSSI) 2010., SCOPUS: ar.j, info:eu-repo/semantics/published

This article provides a meta-analysis of quantitative data available in literature regarding the relation between termite numbers and the volume of their mounds for 24 species belonging to 13 genera. The leading question behind this analysis is: "how do the respiratory gas exchanges regulate the size of termite mounds?" This question is answered through the analysis of the log-log regression between the volume of the mound and the number of inhabitants. The most confident data support the hypothesis of a respiratory regulation that can be achieved through a relation between the termite numbers and (1) the volume of their mounds (slope of the regression near 1, Noditermes), (2) the surface of the outer walls of their mounds (slope of the regression near 0.67, Termitinae and Nasutitermes) or (3) a compromise between the surface of the outer walls of their mounds and some linear structures of their nests (slope of the regression between 0.67 and 0.33, Trinervitermes and Macrotermes). The way this is achieved is linked with the architecture of the mound. A confident relation was found between the number of individuals and the epigeal volume of their mounds for 18 species for which the most reliable data were provided. Three more accurate models are proposed for estimating the termite population based on the nest material and architecture and on the size of the termites. © International Union for the Study of Social Insects (IUSSI) 2010., SCOPUS: ar.j, info:eu-repo/semantics/published

Five genotypes of cowpea (Vigna unguiculata), Bambey 21, Gorom local, KVX61-1, Mouride and TN88-63, grown in pots under glasshouse conditions, were submitted to water deficit by withholding irrigation at vegetative stage (T1) for 14 days, and at flowering stage (T2) for 12 days. Effect of this stress on leaf water potential, gas exchanges, foliar proline, total protein and starch contents, maximal quantum yield of photochemistry (fp0), root volume and yield components was determined. Leaf water potential decreased significantly only for Mouride and TN88-63 (from -0.55 to -0.92 MPa on average) at T2 while root volume, gas exchanges and foliar starch content decreased for the five genotypes under water stress conditions at T1 and T2. fp0 was not affected during water deficit at T1. Significant decrease of fp0 was observed at T2 on the 6th day after stress induction (Dasi) for Gorom, KVX61-1 and TN88-63 and the 10th Dasi for Bambey 21 and Mouride. Proline was significantly accumulated during water stress at the 2 stages, Mouride and TN88-63 showed the highest contents in the case of T2 (2.88 and 3.3 mg.g-1 DM respectively). Water deficit did not affect significantly the total proteins contents for the 5 varieties at T1 and T2. Our results showed that the 5 varieties involved drought avoidance mechanism by decreasing stomatal conductance and transpiration at the 2 stages. Proline accumulation, maintenance of total protein content and starch decrease under stress conditions at T1 and T2 could probably contribute in turgor maintenance. In addition, these solutes contributed probably in the protection of photosynthetic apparatus (PSII) against denaturation notably during water stress at flowering stage. At the two stages water stress reduced significantly seed number per pod and seed number per plant but the genotypic variation observed revealed that Bambey 21 was less affected than Gorom, TN88-63 and Mouride whereas KVX61-1 was most affected. Bambey 21 proved to be tolera

Light and transmission electron microscopy were used to describe the leaf cavity pore of Azolla. The morphological analysis of the pore revealed that it remains open during leaf development as well as in mature leaves. As it seems that there is no obstruction of the pore by any mucilage, gas exchanges between the atmosphere and the inner gaseous compartment of the leaf cavity are likely to occur. The pore, which is cone-shaped and protrudes into the leaf cavity, is limited by two epidermal cell layers. The cells lining the inside of the pore become teat-shaped during pore morphogenesis. Ultrastructural study of these cells showed the presence of a large number of organelles, paramural bodies and 'wart-like' projections at their cell wall surface, suggesting a secretory role. Cytochemical stains showed that these projections are made up of pectin, callose and protein. The role of the pore as well as the possible functions of the teat-cells and their projections are discussed.