INBRE Research UpdateRachel Gross

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

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

SIN

A

ub

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

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

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)

Symptoms: Dark stripe patterns appear when tuber is fried

http://www.apsnet.org/publications/apsnetfeatures/Pages/PotatoZebraChip.aspx

Symptoms: Purple tops, leaf roll, necrosis, chlorsis, premature death

http://www.apsnet.org/publications/apsnetfeatures/Pages/PotatoZebraChip.aspx

Vector: potato-tomato psyllid

http://www.apsnet.org/publications/apsnetfeatures/Pages/PotatoZebraChip.aspx

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

Pathogen EffectorsPathogen

Effector Proteins

PRRs (R genes)

Plant Cell

Resistance (HR cell death)

PAMPs

Resistance

Like Prf

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.

#3

+control

#23

#9

#5

+control

#29

#28

#25

#24

#30

#31

+control

#32

#33

#34GFP (negative control)

+controlPrfdv