The roles of carbonic anhydrases in сarbon concentrating mechanisms of aquatic photoautotrophs

The article surveys multiple roles of carbonic anhydrases (CAs) in inorganic carbon (Ci) acquisition by cyanobacteria, microalgae, and macrophytes under Ci limiting conditions. Slow Ci diffusion in aquatic environments imposes the need for carbon concentrating mechanisms (also named CO2 concentrating mechanisms, CCMs) in aquatic photoautotrophs to transport Ci against the gradient and ensure CO2 supply to photosynthesis. There are common requirements for efficient CCM functioning in cyanobacteria, algae, and aquatic angiosperms, including active transport of HCO3- to the Ci-concentrating compartment and CO2 generation from the HCO3- pool in the Rubisco-enriched subcompartment. Facilitating Ci diffusion in aqueous solutions and across lipid bilayers, CAs play essential roles in CCMs that are best studied in cyanobacteria, green algae, and diatoms. Roles of CAs in CCMs depend on their localization and include facilitation of active transmembrane Ci uptake by its supplying at the outer surface (Role 1) and removal at the inner surface (Role 2), as well as the acceleration of CO2 production from HCO3- near Rubisco (Role 3) in a special CO2-tight compartment, carboxysome in cyanobacteria or pyrenoid in microalgae. The compartmentalization of CAs is also critical because, if activated in the HCO3- –concentrating compartment, they can easily eliminate the Ci gradient created by CCMs.

ECONOMICALY SIGNIFICANT AQUATIC PLANTS OF JALPAIGURI DISTRICT, WEST BENGAL, INDIA

Aquatic angiosperms are actual substantial customs of plant life and are indispensable component of the fresh water biome. Aquatic plants are very remarkable forms of plant life and are essential component of the aquatic ecosystem. A variety of products and significant beneficial services are offered by these groups of organisms to the human society and ecosystem. They play imperative role in the life of human beings as food, fodder, medicine, etc. In spite of that, the knowledge of correct utilization of aquatic plants is lacking among common people and in order to make them aware, steps are to be introduced. In this survey an attempt has been made to categorize aquatic plants and their utilization by the local inhabitants of Jalpaiguri district, West Bengal, India.

First evidence of insect herbivory on Albian aquatic angiosperms of the NE Iberian Peninsula

ABSTRACTEvidence of herbivory on Laurasian Nymphaeaceae leaves from Lower Cretaceous (Upper Albian) deposits is presented for the first time. The types of damage on leaves consist of both hole feeding and margin feeding, which were found on foliar remains of the taxa Ploufolia cerciforme and Aquatifolia cf. fluitans. Within the first category of damage, the Damage Type 78 (DT78) type on Ploufolia leaves and type DT02 on Aquatifolia foliar lamina were recorded. The second category of damage has only been identified in Ploufolia leaves, and it corresponds to type DT12. The subsequent palaeoichnologic interpretation made it possible to compare these records with damage caused by the extant water lily pest to make a possible palaeoecological interpretation.

Pistia and Sagittaria Rupp. ex L. Two Generic Records for Andaman and Nicobar Islands, India

Two aquatic angiosperms, Pistia stratiotes L. (Araceae), and Sagittaria guayanensis ssp. lappula (Alismataceae) collected from Middle Andaman Islands are additions to the flora of the Andaman & Nicobar Islands. Brief introduction description, phenology and distribution are presented along with photographs.

Montsechia, an ancient aquatic angiosperm

The early diversification of angiosperms in diverse ecological niches is poorly understood. Some have proposed an origin in a darkened forest habitat and others an open aquatic or near aquatic habitat. The research presented here centers on Montsechia vidalii, first recovered from lithographic limestone deposits in the Pyrenees of Spain more than 100 y ago. This fossil material has been poorly understood and misinterpreted in the past. Now, based upon the study of more than 1,000 carefully prepared specimens, a detailed analysis of Montsechia is presented. The morphology and anatomy of the plant, including aspects of its reproduction, suggest that Montsechia is sister to Ceratophyllum (whenever cladistic analyses are made with or without a backbone). Montsechia was an aquatic angiosperm living and reproducing below the surface of the water, similar to Ceratophyllum. Montsechia is Barremian in age, raising questions about the very early divergence of the Ceratophyllum clade compared with its position as sister to eudicots in many cladistic analyses. Lower Cretaceous aquatic angiosperms, such as Archaefructus and Montsechia, open the possibility that aquatic plants were locally common at a very early stage of angiosperm evolution and that aquatic habitats may have played a major role in the diversification of some early angiosperm lineages.