Editing Green algae (section)

===Sex pheromone===
[[File:Freshly harvested algae 01.jpg|thumb|Freshly harvested algae]]
[[Sex pheromone]] production is likely a common feature of green algae, although only studied in detail in a few model organisms. ''[[Volvox]]'' is a genus of [[Chlorophyta|chlorophytes]]. Different species form spherical colonies of up to 50,000 cells. One well-studied species, ''[[Volvox carteri]]'' (2,000 – 6,000 cells) occupies temporary pools of water that tend to dry out in the heat of late summer. As their environment dries out, asexual ''V. carteri'' quickly die. However, they are able to escape death by switching, shortly before drying is complete, to the sexual phase of their life cycle that leads to production of dormant desiccation-resistant [[zygote]]s. Sexual development is initiated by a [[glycoprotein]] pheromone (Hallmann et al., 1998). This pheromone is one of the most potent known biological effector molecules. It can trigger sexual development at concentrations as low as 10<sup>−16</sup>M.<ref name="Hallmann-1998">{{cite journal | vauthors = Hallmann A, Godl K, Wenzl S, Sumper M | title = The highly efficient sex-inducing pheromone system of Volvox | journal = Trends in Microbiology | volume = 6 | issue = 5 | pages = 185–9 | date = May 1998 | pmid = 9614342 | doi = 10.1016/s0966-842x(98)01234-7 }}</ref> Kirk and Kirk<ref name="Kirk-1986">{{cite journal | vauthors = Kirk DL, Kirk MM | title = Heat shock elicits production of sexual inducer in Volvox | journal = Science | volume = 231 | issue = 4733 | pages = 51–4 | date = January 1986 | pmid = 3941891 | doi = 10.1126/science.3941891 | bibcode = 1986Sci...231...51K }}</ref> showed that sex-inducing pheromone production can be triggered experimentally in [[Somatic (biology)|somatic]] cells by [[heat shock]]. Thus heat shock may be a condition that ordinarily triggers sex-inducing pheromone in nature.<ref name="Hallmann-1998" />

The ''Closterium peracerosum-strigosum-littorale (C. psl)'' complex is a unicellular, isogamous [[Charophyceae|charophycean]] alga group that is the closest unicellular relative to land plants. [[Heterothallic]] strains of different [[mating type]] can conjugate to form [[zygospore]]s. Sex pheromones termed protoplast-release inducing proteins (glycopolypeptides) produced by mating-type (-) and mating-type (+) cells facilitate this process.<ref name="Sekimoto-1990">{{cite journal | vauthors = Sekimoto H, Satoh S, Fujii T | title = Biochemical and physiological properties of a protein inducing protoplast release during conjugation in theClosterium peracerosum-strigosum-littorale complex | journal = Planta | volume = 182 | issue = 3 | pages = 348–54 | date = October 1990 | pmid = 24197184 | doi = 10.1007/BF02411384 | s2cid = 1999634 }}</ref>