Prokaryotes
1. Bacteria are classified into two
kingdoms: Eubacteria (true
bacteria) and Archaebacteria
(Ancient Bacteria).
2.  They lack of a cell nucleus and
other organelles with double
membrane
3. Region called the NUCLEOID
which has a single circular
chromosome, accessory rings of
DNA called PLASMIDS
binary transverse fission and budding
Each bacterium divides following
unequal cell growth; the mother cell
is retained, and a new daughter cell
is formed.
Most bacteria reproduce by a
process of binary transverse fission
Sporulation
–  endospores in Bacillus
and Clostridium
–  cysts in Azotobacter
–  heterocysts in some
cyanobacteria.
Bacterial gene exchange
pilius CONJUGATION (exchange of DNA)
TRANSFORMATION- bacteria incorporate
genes from dead bacteria
TRANSDUCTION - viruses insert
new genes into bacterial cells
Inclusions
Inclusions are reserve deposits found in prokaryotic and eukaryotic
cells.
• 
• 
• 
• 
• 
inorganic phosphate
polysaccharide granules
lipids
reserve carbon
gas vacuoles (cyanobacteria)
Acidocalcisomes
Acidocalcisomes are electron-dense acidic organelles rich in calcium
and polyphosphate described in several parasites, algae, and slime
molds.
»  Functions
•  storage of cations and phosphorus
•  polyphosphate metabolism
•  calcium homeostasis
•  maintenance of intracellular pH
•  osmoregulation.
Acidocalcisomes
Agrobacterium tumefaciens
have flagella, it lives in
the soil and
accumulates in the
rhizosphere around
roots.
Induces root tumors, and
carries the distinct Ri
(root-inducing) plasmid.
Acidocalcisomes
Agrobacterium tumefaciens attacks a broad spectrum of woody and
herbaceous plants
Euonymoum
Brambles
Grape
Maple
Rose
Willow
Cyanobacteria the blue-green algae
Photosynthetic
Chlorophyll a
Phycobilins
–  Phycocyanin
–  Phycoerithrin
Thylacoids
Glycogen
Cyanobacteria the blue-green algae
Each cell is individual
Joined by walls or mucilaginous sheaths
Cyanobacteria the blue-green algae
Specialized cells
Necridia
Hormogonia
Cyanobacteria the blue-green algae
Akinetes
•  Asexual propagules derived from vegetative cells.
•  Very thick walls.
•  Survive unfavorable conditions
•  Their thylakoids are not organized
for photosynthesis.
•  Contain cyanophycin granules (Amino Acids) and lipids
Cyanobacteria the blue-green algae
Heterocyst
• 
• 
• 
• 
• 
• 
N2 fixation
N  ammonium (NH4+)
Thick cell wall
Low oxygen concentration
Photosystem II inactive
Connected to vegetative
cells by cell wall pores
Symbiotic associations
Azolla is a small water fern that assimilates nitrogen in symbiotic
association with Anabaena azollae.
The algal symbiont resides in the leaf cavity of Azolla in exchange for
nutrients and carbon sources.
Rhizobium
Soil bacteria that fix nitrogen
Endosymbiotic association with legumes
root nodules
Prochlorophytes
prokaryotes that carry out oxygenic photosynthesis using chlorophylls a
and b, but lack phycobili-proteins as light-harvesting pigments
Prochloron
Prochlorothrix
Prochlorococcus
Mycroplasma
No cell walls
Can assume various
forms
Spiroplasma citri causes stubborn disease in
grapefruit and sweet oranges
Phytoplasm
They are mycoplasmalike
organisms
Parasites
Passive or active
Attack the sieve tube elements in
the phloem
Transmitted from plant to plant by
insects
Pseudomonas
Xanthomonas
Viruses
  Obligate intracellular parasites
of
•  Plants
•  Animals
•  Fungi
•  Bacteria
  protein coat
  nucleic acid core
DNA or RNA
  They cannot carry out
metabolism
Plant viruses
600 kinds of plant viruses
2000 plant diseases
Common symptoms:
Chlorotic or necrotic tissues
Plant viruses
DNA viruses
Geminiviruses (groups of two)
Badnaviruses (Bananas)
Caulimoviruses (Cauliflower)
Transmission from plant to plant
Vectors with piercing and sucking mouthparts
wounds
From infected pollen to the ovule
Inside the plant via plasmodesmata
Phloem
Movement proteins