Localization of pectins and Ca2+ ions in unpollinated and pollinated wet (Petunia hybrida Hort.) and dry (Haemanthus albiflos L.) stigma.

The subcellular localization of Ca2+ ions as well as esterified and deesterified pectins in unpollinated and pollinated wet (Petunia hybrida) and dry (Haemanthus albiflos) stigma was analyzed. Stigmas with different surfaces were found to differ in Ca2+ and pectin localization. In a wet Petunia hybrida stigma, Ca2+ ions were present in the exudate occurring in the intercellular spaces of secretory tissue before pollination. The exudate of an unpollinated stigma was the site of the localization of large amounts of deesterified pectins. Stigma penetration by pollen tubes induced the lysis of this category of pectins. The epidermal cells walls of the dry Haemanthus albiflos stigma before pollination lacked free and loosely bound Ca2+ ions. Pollination induced an accumulation of these ions in the apoplast of the stigma epidermal cells. In cells walls of an unpollinated stigma, mainly esterified pectins were present. Their deesterification took place after pollination at the site of pollen grain adhesion and then at the site of pollen tube growth. These results have shown that wet and dry stigmas differ in pectin metabolism and in the mechanism of forming a calcium environment at the site of pollen grain germination

Localization of pectins and Ca2+ ions in unpollinated and pollinated wet (Petunia hybrida Hort.) and dry (Haemanthus albiflos L.) stigma.

The subcellular localization of Ca2+ ions as well as esterified and deesterified pectins in unpollinated and pollinated wet (Petunia hybrida) and dry (Haemanthus albiflos) stigma was analyzed. Stigmas with different surfaces were found to differ in Ca2+ and pectin localization. In a wet Petunia hybrida stigma, Ca2+ ions were present in the exudate occurring in the intercellular spaces of secretory tissue before pollination. The exudate of an unpollinated stigma was the site of the localization of large amounts of deesterified pectins. Stigma penetration by pollen tubes induced the lysis of this category of pectins. The epidermal cells walls of the dry Haemanthus albiflos stigma before pollination lacked free and loosely bound Ca2+ ions. Pollination induced an accumulation of these ions in the apoplast of the stigma epidermal cells. In cells walls of an unpollinated stigma, mainly esterified pectins were present. Their deesterification took place after pollination at the site of pollen grain adhesion and then at the site of pollen tube growth. These results have shown that wet and dry stigmas differ in pectin metabolism and in the mechanism of forming a calcium environment at the site of pollen grain germination

Anticancer agents found in environment affect Daphnia at population, individual and molecular levels

Pharmaceuticals are used in medical treatment on a large scale and as a waste contaminate freshwater ecosystems. Growing amount of so-called civilization diseases, such as different type of cancer, significantly contribute to this form of pollution. The aim of the present study was to determine how the exposure to chemotherapeutics: cyclophosphamide (CP) and cisplatin (CDDP), at detected in environment concentrations, influence proteome profile, life history and population parameters of naturally setting surface waters Daphnia pulex and Daphnia pulicaria. The parameters important for crustaceans, survivorship and population growth rate, were importantly decreased by CDDP treatment but not influenced by CP. On the contrary, the individual growth rate was affected only by CP and exclusively in the case of D. pulicaria. In both clones treated with CP or CDDP, decreased number of eggs was observed. Interestingly, Daphnia males were less sensitive to tested chemotherapeutic than females. Proteome profile revealed that tested anticancer pharmaceuticals modified expression of some proteins involved in Daphnia metabolism. Moreover, males exposed to CDDP showed increased level of enzymes participating in DNA repair. Summing up, the contaminating environment chemotherapeutics reduced fitness of naturally occurring Daphnia species. In consequence this may affect functioning of the aquatic food webs