Biotechnological approaches in Host Plant Resistance (HPR)

1. Welcome

2. POST GRADUATE INSTITUTE
MAHATMA PHULE KRISHI VIDYAPEETH, RAHURI
Biotechnological approaches in Host Plant Resistance (HPR)
Presented by
Mr. Ankush Wankhade
(Ph. D 2017/08)

3. UNIT III. Biotechnological approaches in Host Plant Resistance plant
A. Genetic manipulation of secondary plant substances
B. Incorporation of resistant genes in crop varieties

4. Genetic manipulation of secondary plant substances
Before going to start genetic manipulation of secondary plant metabolites, we should
know
• What is mean by Secondary Metabolites?
• Which are the different types of secondary metabolites
• What is the role of secondary metabolites?
• How it protects the plant from different stresses
• What is the procedure for its genetic manipulation in plant?

5. Figure : Biotic, abiotic and man related factors that can induce stress
related reactions in terrestrial plants

6. Figure 4. Many modes of anti-pathogenic defense are induced by
infection. Fragments of pathogen molecules called elicitors initiate a
complex signaling pathway leading to the activation of defense
responses

7. Figure 2. Biosynthetic relationship among some primary and
secondary metabolites. The principal group of secondary
metabolites are circled.

8. What is the procedure for genetic manipulation of secondary metabolites in
plant?
We can better explain it by taking example for terpenoides secondary metabolite compound.
For genetic manipulation of biosynthesis following factor is essential
Gene promoter-
It drive expression of gene at particular time in specific place
it interact with RNA polymerase
Transcription factor-
It is master regulatory genes which repressing or promoting RNA polymerase binding with to
specific promoter region

9. Subcellular localization-
Localization of genes (TPS) and appropriate prenyl diphosphate synthase in
mitochondria or plastids is preferable to cytosolic localization due to the tightening
regulation of cytosolic prenyl diphosphate pools. By introduction of potent antimalarial
drug (artemisinin) in tobacco via two mega biosynthetic pathways into the nuclear
genomes and chloroplasts, resulted in enhanced level of artemisinin without interrupting
plant health.
Host organism selection –
should be done carefully

10. B. Incorporation of resistant genes in crop varieties

12. Now a day’s most of the scientists are use gene pyramiding technique to produce resistant verities. To
understand above heading one recent work has taken as example in which scientists has introgressed
bacterial blight resistance in Samba Mashuri, an elite indica rice variety by using Marker Assisted
Backcrossing
Samba Mahsuri (BPT5204) is a medium slender grain indica rice variety that is very popular with
farmers and consumers across India because of its high yield and excellent cooking quality. However,
the variety is susceptible to several diseases and pests, including bacterial blight (BB). We have used
PCR based molecular markers in a backcross-breeding program to introgress three major BB resistance
genes (Xa21, xa13 and xa5) into Samba Mahsuri from a donor line (SS1113) in which all the three genes
are present in a homozygous condition. At each backcross generation, markers closely linked to the
three genes were used to select plants possessing these resistance genes (foreground selection) and
microsatellite markers polymorphic between donor and recurrent parent were used to select plants
that have maximum contribution from the recurrent parent genome (background selection). A selected
BC4F1 plant was selfed to generate homozygous BC4F2 plants with different combinations of BB
resistance genes. The three-gene pyramid and two gene pyramid lines exhibited high levels of
resistance against the BB pathogen. Under conditions of BB infection, the three-gene pyramid lines
exhibited a significant yield advantage over Samba Mahsuri. Most importantly, these lines retain the
excellent grain and cooking qualities of Samba Mahsuri without compromising the yield as determined
in multi-location trials. This work demonstrates the successful application of marker-assisted selection
for targeted introgression of multiple resistance genes into a premium quality rice variety (Raman
M. et. al 2008)

13. Thank you