1. INBRE Research Update
Rachel Gross

2. Project 1: SINA Interacting Proteins
through Yeast Two-Hybrid Screening
• Understanding Degradation for Cellular Health

3. SINAs role in Degradation
•SINA is group of E3 ligase proteins that labels different targets
within the cell to be degraded.
•Studies have shown that some SINAs are involved in defense
regulation
Defense
Protein
No
Pathogen
Defense
Protein
No
Pathogen
ub

4. Screening for Interacting Proteins
• Using cDNA from tomato, cut
into fragments and placed into
yeast cells with SINAs.
•Colonies with interacting proteins
turn blue on special plates
•Next step: isolate the interacting
gene and sequence

5. Findings so far:
• Promoter-binding-like protein: Transcription factor
• Sec61 alpha-like subunit: fungal resistance
• CBSD containing transcription: very little information on this protein
• chitin synthesis: fungal resistance primary defense line
• RALF-like protein: involved in plant growth regulation
• CDC5-like protein: cell cycle regulation

6. Project 2: Zebra Chip Effectors
• Zebra Chip Disease is a relatively new bacterial infection
that was first observed in Mexico in the late 1990s and
appeared in Texas in 2000.
• Symptoms: easily confused with other diseases until the
processing time
• Signs: very little is known
• Vector: Potato-Tomato psyllid (Bactericera cockerelli)

7. Symptoms: Dark stripe patterns appear
when tuber is fried
http://www.apsnet.org/publications/apsnetfeatures/Pages/PotatoZebraChip.aspx

8. Symptoms: Purple tops, leaf roll,
necrosis, chlorsis, premature death
http://www.apsnet.org/publications/apsnetfeatures/Pages/PotatoZebraChip.aspx

9. Vector: potato-tomato psyllid
http://www.apsnet.org/publications/apsnetfeatures/Pages/PotatoZebraChip.aspx

10. Signs
• Using PCR scientists were able to identify regions of the
pathogens DNA that are related to citrus greening complex
(a bacterial pathogen also vectored by the psyllid) and so
they named the new pathogen Candidatus Liberibacter
psyllaurous
• Preliminary studies show that Ca. Liberibacter can be
transmitted plant to plant or through the psyllid population.
http://www.apsnet.org/publications/apsnetfeatures/Pages/PotatoZebraChip.aspx

11. Pathogen Effectors
Pathogen
Effector
Proteins
PRRs
(R genes)
Plant Cell
Resistance
(HR cell death)
PAMPs
Resistance
Like Prf

12. Cell Death Assay using Agrobacterium
• Mix each effector with mutant defense protein Prf-turns on
HR
• Use Prfᵈ¹⁴¹⁶ᵛ with GFP as a positive control
• Use GFP alone as negative control
• If cell death is delayed or not present, it suggests the
effectors are silencing the HR cell death response-block Prf
pathway.

13. #3
+control
#23
#9
#5
+control
#29
#28
#25
#24

14. #30
#31
+control
#32
#33
#34
GFP (negative
control)
+controlPrfdv