Plastids are a class of organelles, and organelles include chloroplasts. Chloroplasts contain the green pigment chlorophyll, which converts light into useful cell energy in a process known as photosynthesis.
Since the 1960s, biologists have debated how the first plant species arose between a billion and a billion and one-half years ago. The most widely held theory is that a plastid joined blue-green algae (a cyanobacterium) to form the first plant.
A research time at the Bhattacharya Laboratory at Rutgers University, led by Dana Price, analyzed the DNA of plastids from the glaucophyte yanophora paradoxa, a very primative algae. This DNA was compared to the DNA from plastids of other algae (both red and green) as well as DNA from various land plants.
The paradoxa plastid DNA retained clues that it evolved from early cyanobacteria, as it includes genes needed to fermentation and starch biosynthesis. The DNA also has genes similar to ancient bacteria akin to the Chlamydiae bacteria, and these genes allow the products of photosynthesis to be exported to the rest of the cell and for the photosynthate to be combined into polysaccharides for storage.
Genetic analysis suggests that the cyanobacterium was incorporated just once, requiring cooperation among the host cell, the cyanobacterium (which can perform photosynthesis) and the Chlamydia-like bacterium (which is capable of making the products of photosynthesis available to the host).
The genetic analysis suggests the incorporation of the cyanobacterium must have occurred just once and that it required cooperation between the host cell, the photosynthesizing cyanobacterium, and a Chlamydia-like bacterium. The cyanobacterium (now called a plastid) provided food from sunlight, and the other bacterium made the products of photosynthesis available to the host.
The article linked below notes:
"Dr Bhattacharya, after whom the laboratory at Rutgers University is named, said that the three components together formed the new organelle, but that genes would also have been recruited from multiple sources before cell walls were developed."
The research was published in the journal Science.
The information provided above is summarized from Lin Edwards write up of February 17, 2012, in PhysOrg.com news at:
http://www.physorg.com/news/2012-02-ancestor.html
Since the 1960s, biologists have debated how the first plant species arose between a billion and a billion and one-half years ago. The most widely held theory is that a plastid joined blue-green algae (a cyanobacterium) to form the first plant.
A research time at the Bhattacharya Laboratory at Rutgers University, led by Dana Price, analyzed the DNA of plastids from the glaucophyte yanophora paradoxa, a very primative algae. This DNA was compared to the DNA from plastids of other algae (both red and green) as well as DNA from various land plants.
The paradoxa plastid DNA retained clues that it evolved from early cyanobacteria, as it includes genes needed to fermentation and starch biosynthesis. The DNA also has genes similar to ancient bacteria akin to the Chlamydiae bacteria, and these genes allow the products of photosynthesis to be exported to the rest of the cell and for the photosynthate to be combined into polysaccharides for storage.
Genetic analysis suggests that the cyanobacterium was incorporated just once, requiring cooperation among the host cell, the cyanobacterium (which can perform photosynthesis) and the Chlamydia-like bacterium (which is capable of making the products of photosynthesis available to the host).
The genetic analysis suggests the incorporation of the cyanobacterium must have occurred just once and that it required cooperation between the host cell, the photosynthesizing cyanobacterium, and a Chlamydia-like bacterium. The cyanobacterium (now called a plastid) provided food from sunlight, and the other bacterium made the products of photosynthesis available to the host.
The article linked below notes:
The research was published in the journal Science.
The information provided above is summarized from Lin Edwards write up of February 17, 2012, in PhysOrg.com news at:
http://www.physorg.com/news/2012-02-ancestor.html
No comments:
Post a Comment