How do rhodophyta grow

The PyKPA1 gene, which encoded a sodium pump, was differentially expressed in the gametophyte as compared to the sporophyte, which seems to depend on the presence of specific promoter elements Uji et al.

In this regard, carposporophyte-specific genes were identified in Gracilariopsis andersonii Kamiya et al. In Gracilaria lemaneiformis , a female gametophyte-specific gene, GMF, has been reported Chen et al. In Griffithsia japonica , the GjFP-1 gene, encoding a heat-shock protein 90, may be involved in the differentiation of female gametophyte Lee et al. Other approaches have made it possible to reach candidate gene s involved in reproduction.

From our point of view this could only be started to achieve using a species that is easy to handle, with relatively short generation times, and fulfills the criteria needed to undergo genetic transformation, which constitutes the current bottleneck in the molecular biology of seaweeds see Mikami, In photosynthetic eukaryotes, like algae, light is the driving force for growth and development; it is the source of energy, but also the signal triggering both vegetative and reproductive developmental events.

In turn, the existence and the type of photoreceptors in aquatic organisms have attracted scientific attention, due to the peculiar characteristics of the interaction of light in the aquatic environment. Thus, the presence of diverse genuine photoreceptors, such as phototropins, aurochromes blue absorbing , neochromes—a kind of chimeric phytochrome, cryptochromes, and phytochromes in marine algae has been reported and reviews have been produced, which include future applied dimensions Kianianmomeni and Hallmann, Interestingly, as far as signal transduction is concerned, the phototropin mechanism seems to be conserved between algae and higher plant Huang et al.

In seaweeds, plant hormones have been reported to affect growth and development Chan et al. Concerning reproduction events, in Grateloupia imbricata as G. In recent years extensive knowledge has been accumulated about light, photoreceptors and plant hormone interaction, and crosstalk at the molecular level in higher plants, particularly during the events occurring at two physiological scenarios: seedling photomorphogenesis and shade avoidance Gyula et al.

Table 1 provides an overview of the complex system operating in the light—photoreceptors—plant hormones integrated network.

All of this important information has so far proved to be relevant to higher plants, particularly for the model species Arabidopsis thaliana , and it is completely unknown whether the key elements highlighted also operate in seaweeds, despite the fact that the influence of photoreceptors and plant hormones on reproduction has been reported, as previously mentioned.

Other factors affecting plant growth and development, like circadian clock sensors that control endogenous levels of plant hormones i. Finally, by way of future perspective, in our laboratory we have recently adopted Bonnemaisonia hamifera Bonnemaisoniaceae as a working species.

Cultures of the sporophyte Trailliella phase have been established so far, and work is progressing toward the induction of the differentiation of gametophytes, using temperature and photoperiod, and plant hormones Figures 1A—C.

Should the completion of the life cycle may be accomplished in the next future as a basic requirement for a working species, it remains to find an appropriate genomic structure a compact or simple genome, a small number of genes, important functional transcriptomic information, etc. Nevertheless, even in the long run, with B. The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Agrawal, S. Factors controlling induction of reproduction in algae. Folia Microbiol. Molecular interaction between light and hormone signalling to control plant growth. Plant Mol. Arun, A. Non-cell autonomous regulation of life cycle transitions in the model brown alga Ectocarpus. New Phytol.

Baweja, P. Seaweed tissue culture as applied to biotechnology: problems, achievements and prospects. Bornette, G. Response of aquatic plants to abiotic factors: a review. Chan, C. Porphyra Bangiophyceae transcriptomes provide insights into red algal development and metabolism. Trends in seaweed research. Trends Plant Sci. Chen, P. Cloning and characterization of a female gametophyte-specific gene in Gracilaria lemaneiformis Gracilariales, Rhodophyte.

Cock, J. The Ectocarpus genome and the independent evolution of multicellularity in brown algae. Nature , — Coelho, S. Cole, K. Biology of the Red Seaweeds. New York: Cambridge University Press. Google Scholar. Bourgougnon London: Elsevier , 53— Genome structure and metabolic features in the red seaweed Chondrus crispus shed light on evolution of the Archaeplastida.

Drew, K. Conchocelis-phase in the life-history of Porphyra umbilicalis L. Life-history of Porphyra. Dring, M. Photo control of development in algae. Plant Physiol. Fernando, A. The genetic basis of flowering responses to seasonal cues. Differential expression of the ornithine decarboxylase gene during carposporogenesis in the thallus of the red seaweed Grateloupia imbricata Halymeniaceae. Effects of ethylene on tetrasporogenesis in Pterocladiella capillacea Rhodophyta.

Influence of plant growth regulators, polyamines and glycerol interaction on growth and morphogenesis in carposporeling of Grateloupia doryphora cultured in vitro. Male and female gametophytes are often separate. The male gametophytes produce male nonflagellated gametes called spermatia. Female gamethophytes produce a special branch, the carpogonial branch, that produces a terminal carpogonium oogonium, an egg-bearing structure. Contact between spermatia and carpogonia is facilitated bywatermovements.

The carposporophyte is a diploid stage that develops fromthe zygote fertilized carpogonium and produces carpospores. Diploid tetrasporophytes develop from carpospores. Tetrasporophytes form tetrasporangia, which produce four haploid tetraspores.

When released, tetraspores develop into new gametophytes. The gametophyte and tetrasporophyte may appear nearly identical, and therefore can be said to be isomorphic, as in the Polysiphonia. Alternatively, the tetrasporophyte and gametophytemay be very different in size and appearance heteromorphic , as in Phyllophora.

Diversity of Red Algae Red algae are divided into two subclasses or classes: Florideophyceae florideophyceans or floridean and Bangiophyceae bangiophyceans or bangean. Floridean algae have numerous small chloroplasts and a complex life cycle.

Bangean algae have life cycles without carpogonia and carposporophyte development and have a single central chloroplast. Representatives of Bangiophyceae include Porphyra, Bangia, and Cyanidium.

Uses People have used red algae for thousands of years. Most are collected along seashores for use in human food or for the extraction of gelling compounds. A few red algae, such as Porphyra, Eucheuma, and Gracilaria, are cultivated. The most valuable of all algae is Porphyra. The annual Porphyra harvest worldwide has been estimated to be worth 2.

Porphyra in Japanese, Nori; in Chinese, Zicai is used as a wrapper for sushi or may be eaten mixed with rice and fish and in salads. It is very rich in vitamins B and C as well as minerals, including iodine. There are about seventy species of Porphyra, but the most widely used species is Porphyra yezoensis.

Two important compounds derived from red algae are agar and carrageenan, both of which are polymers of galactose. Agar is used as a medium for culturing microorganisms, including algae; as a food gel for jams and jelly ; and in pharmaceutical capsules.

In the United States, agar is used in the canning industry as a protective agent against the unwanted effects of metals. In addition, agar is the source of agarose, which is widely used in recombinant DNA deoxyribonucleic acid technology for gel electrophoresis.

The first agar was produced in in Japan, and Japan is still the largest producer of agar. The red algae Gelidium, Gracelaria, and Pterocladia are harvested for extraction of agar. Carrageenan is used in toothpaste, cosmetics, and food, such as ice cream and chocolate milk. Eucheuma, Kappaphycus, and Chondus the so-called Irishmoss are the sources of carrageenan. The most important producer of carrageenan is Europe, followed by the Philippines and Indonesia.

Email This BlogThis! Most algae is green or brown. Red algae, however, contain a variety of pigments, including chlorophyll, red phycoerythrin, blue phycocyanin, carotenes, lutein, and zeaxanthin. The most important pigment is phycoerythrin, which provides these algae with their red pigmentation by reflecting red light and absorbing blue light. Not all of these algae are a reddish color, though, as those with less phycoerythrin may appear more green or blue than red due to the abundance of the other pigments.

Red algae are found around the world, from polar waters to the tropics, and are commonly found in tide pools and in coral reefs. They also can survive at greater depths in the ocean than some other algae, because the phycoerythrin's absorption of blue light waves, which penetrate deeper than other light waves do, allows red algae to carry out photosynthesis at a greater depth. Some common examples of red algae species include Irish moss, dulse, laver nori , and coralline algae. Coralline algae help to build tropical coral reefs.

These algae secrete calcium carbonate to build hard shells around their cell walls. There are upright forms of coralline algae, which look very similar to coral, as well as encrusting forms, which grow as a mat over hard structures such as rocks and the shells of organisms such as clams and snails. Coralline algae are often found deep in the ocean, at the maximum depth that light will penetrate the water. Red algae are an important part of the world's ecosystem because they are eaten by fish, crustaceans , worms, and gastropods, but these algae are also eaten by humans.

Nori, for example, is used in sushi and for snacks; it becomes dark, almost black when it is dried and has a green hue when cooked.

Irish moss, or carrageenan, is an additive used in foods including pudding and in the production of some beverages, such as nut milk and beer. Red algae are also used to produce agars, which are gelatinous substances used as a food additive and in science labs as a culture medium. Red algae are rich in calcium and sometimes are used in vitamin supplements.