POLYAMINES

 

FOUND IN ALL ORGANISMS; MICROORGANISMS, ANIMALS AND PLANTS

 

POLYAMINES ARE COMPOUNDS CONTAINING TWO OR MORE AMINE GROUPS

 

H2N-(CH2)4-NH2     PUTRESCINE

 

H2N-(CH2)3-NH-(CH2)4-NH2                               SPERMIDINE

 

1.   FIRST OBSERVED AS CRYSTALS IN

   HUMAN SEMEN

 

2.   FIRST OBSERVED BY VAN    LEEUWENHOEK

 

3.   CHARACTERIZED IN THE 1920íS

 

4. OF INTEREST TO PLANT

   PHYSIOLOGISTS IN THE EARLY

   1970íS

 

 

 

   1.   DERIVED FROM THE AMINO             ACIDS ARGININE AND LYSINE

 

   2.   INVOLVES S-                       ADENOSYLMETHIONINE, AN             INTERMEDIATE IN ETHYLENE         BIOSYNTHESIS

 

   3.   OFTEN APPEAR ASSOCIATED             WITH PHENOLIC COMPOUNDS

 

      a.   HYDROXYCINNAMIC ACID

 

      b.   COUMARIC ACID

 

      c.   CAFFEIC ACID

 

MODE OF ACTION:

 

   1.   AT NORMAL INTRACELLULAR pH,

      POLYAMINES ARE POLYCATIONIC

      (CARRY MULTIPLE POSITIVE

      CHARGES)

 

   2.   POLYAMINES BIND TO NUCLEIC

      ACIDS AND THE PHOSPHOLIPIDS      OF THE PLASMA MEMBRANE            BECAUSE THEY ARE                  POLYANIONIC (CARRY MULTIPLE      NEGATIVE CHARGES)

 

   3.   BINDING AFFECTS THE               SYNTHESIS OF MACROMOLECULES    AND MEMBRANE PERMEABILITY

 

   4.   THERMOPHILIC BACTERIA PRO-

      DUCE POLYAMINES TO PROTECT

      AGAINST THERMAL                      INACTIVATION OF ENZYMES AND

      TO STABILIZES THE DNA FROM

      THERMAL DENATURATION

 

   5.   ROLES IN PLANTS INCLUDE:

 

      a.   STABILIZING OAT PROTO-

         PLASTS

 

      b.   INFLUENCE CELL DIVISION

         AND EMBRYOGENESIS IN

         CARROT TISSUE CULTURES

 

      c.   DELAY SENESCENCE

 

HYPOTHETICAL PLANT HORMONES

 

   1.   FLORIGEN - HORMONE RESPONS-

      IBLE FOR FLOWERING

 

      a.   HAS NEVER BEEN ISOLATED

 

   2.   VERNALIN - ACCOUNTS FOR THE

      EFFECT OF LOW TEMPERATURE        ON FLOWERING OF WINTER

      CEREALS AND BIENNIALS

 

OTHER BIOLOGICALLY ACTIVE SUBSTANCES

 

1.   BRASSINS AND BRASSINOSTEROIDS

 

   a.   ISOLATED FROM POLLEN OF

      THE RAPE PLANT                      (BRASSICACEAE)

 

  

 

b.   PRESENT IN EXTREMELY SMALL

   QUANTITIES

 

   1.   500 POUNDS OF RAPE POLLEN

      YIELDS 10 MG OF CRYSTALLINE

      BRASSINOLIDE

 

c.   HAVE BEEN ISOLATED FROM,

 

   1.   POLLEN

 

   2.   STEMS

 

   3.   FLOWERS

 

   4.   LEAVES

 

d.   EFFECTS:

 

   1.   STIMULATES ELONGATION OF

      HYPOCOTYL AND EPICOTYL            TISSUES FROM LEGUMES AND         COLEOPTILE TISSUES FROM          WHEAT

 

   2.   MAY WORK SYNERGISTICALLY

      WITH AUXIN

 

PHENYLALANINE DERIVATIVES

     

1.   COUMARIN - NATURALLY OCCURING    UNSATURATED LACTONES

 

   a.   HAVE AN AFFECT ON GRASSES

      AND LEGUMES

 

      1.   INHIBITS AUXIN INDUCED

         ELONGATION AT HIGH

         CONCENTRATIONS

 

      2.   STIMULATES ELONGATION AT

         LOW CONCENTRATIONS

 

      3.   INHIBITS SEED                   GERMINATION

 

   2.   TRANSCINNAMIC ACID

      a.   WORKS AS AN ANTIAUXIN

         IN STEM SEGMENT ASSAY

      b.   HAS NO EFFECTS ON INTACT        PLANTS