symbiosis establisment between leguminous plant and rhizobacteria,cell morphogenesis and patterning,cell signaling,nod factor,leguminous plant,rhizobacteria,nitrogen fixation

1. Signaling in bacteria and legumionus
plants during nitrogen fixation
,signaling during cell morphogenesis
and patterning
Submitted to:- submitted by:-
Dr.ashun sir UDAYPAL
CUHP20PLS30

2. NITROGENESE COMPLEX ENZYME
REDUCTASE NITROGENESE
Small componant Large componant
Contain Fe protein Contain Fe,Mo protein
Homodiemer tetramar
Consist two types of enzymes

3. • 8 H+ + 8 e- + N2 + 16 ATP → 2NH3 + 16 ADP + 16 Pi
Reductase cause reduction in nitrogenese transfer
electron Fd to P-cluster and than P-cluster to Fe-Mo
cluster
Nitrogenese cause reduction in nitrogen and convert into
NH3
Reductase require 2ATP for transfer of one electron
Total 16ATP require for formation of 2 NH3 from N2

4. ROOT NODULE FORMATION
• When plant face nitrogen deficiency release some
chemicals Flavinoids Isoflavinoids these chemicals
arttract bacteria
• Bacteria attach to root hair and root hair start curling
• Bacteria digest root cell wall and form infection tube
• Golgi vesicles form infection tube by fusing together
• Bacteria enter in cortex through infection tube and
cortex cell start divide and form nodule
• Nodule contain high amount of bacteria that fix
nitrogen

5. PLANT GENES RHIZOBIAL GENES
Called Nodulin (Nod) genes Called Nodulation(nod ) genes
Nodulation genes classified in two groups:-
COMMON GENES HOST SPECIFIC GENES
nodA ,nodB,and nodC (Present in all
rhizobia)
nodE,nodF,nodH,nodL,nodP,nodQ(found
only in specific species)
Product of common genes require for
synthesis of nod factor
Product of these gens reuire for chemical
modification of nod factor
Nod factor:-
It is a lipo-chitin-oligosaccharide syntyesized by
symbiotic bacteria in response of nodulation signal
In Nod factor sugar residue linked by beta 1-4 Glycosidic bond
Fatty acid (16-18c)long present on 2nd postion of non-reducing
sugar end

6. ENZYME Gene FUNCTION
Acyl-transferase nodA Catalyse addition of fatty
acid
Deacetylase nodB Remove acyl groups
Chitin-synthatase nodC Catalyse synthesis of
chitin
NodE,NodF Determine the length and degree of
saturation of fatty acyl-chain
NodL Add or remove specific group on Nod-
factor

7. Nod-factor function
1.Act as a signal for symbiosis 2.Induce curling in root hair
3.Induce expression of Noduline genes 4.Trigger cell divisine in plant

8. • Nod factor bind with receptor of root hair cell
and increase calcium level in cell by IP3-DAG
pathway
• High calcium activate Nod sensitive
transcription factor(GRAR,ERF) that trigger
expression of nodulin genes and establish
symbiosis
EXPRESSION OF COMMON AND HOST SPECIFIC
GENES:-
When bacteria present in free soil then it not secrete Nod factor
But when it get signal then it start Nod factor formation (in
response of falvinoids )
Flavinoids bind with NodD protein expression of NodD genes is
constitutive

9. NodD protein is a transcription factor that bind with Nod box and
induce expression of common and host specific genes
Exprssion of common and host specific genes is inducible

10. Signaling during cell morphogenesis
and patterning
• Non-canonical Pathway(beta-cat independent):-
require for cell shape change ,cell
morphogenesis ,cell mortility or ca+2 release
after dovelopment of cell
(1)PATHWAY-1:-
wnt bind with frizzled receptor Ryk and
Ror act as a co-receptor that activate Rho-GTPase
and start cytoskeleton recognization and change cell
shape and behavior

12. (1)PATHWAY-2:-
wnt bind with frizzled receptor and
Disheveled bind with inner side of frizzled receptor.
Disheveled activate Rho-GTPase(Daam1 mediates
activation) that cause cytoskeleton recognization or
Gene expression that change cell behaviour and
shape
Daam1 also mediates actin polymerization through the
actin binding protein Profilin(require for monomer
assembly of actin fillament)
Actin form a network through cytoplasam that provide
structural framework for cell shape ,position of
orgenelles,organization of cytoskeleton

13. (3)PATHWAY-3:-
Wnt bind with frizzled receptor that break PIP2 into
IP3and DAG
IP3 open calcium chennal or ER and release calcium from ER
Concentration of cytosolic calcium increase that act as a secondry
messenger and activate PKC(protein kinase –c)
PKC activate transcription factors by phosphorylation and start
transcription and provide structural framework to cell and cell shape
(4)PATHWAY-4:-
Wnt bind with Ryk/Ror receptor that directly
open calcium chennal of ER and increase cytosolic calcium
level
Calcium act as a secondry messenger and activate PKC that
activate transcription factors by phosphorylation and induce
cell shape and function change

14. Thank you