By Emily Keator and Phoebe Parrish

: Part

04-17-14

What Does Iron Do?

• Highly reactive—involved in many redox reactions

• Involved in photosynthesis & cellular respiration as part of the ETC

• Toxic in high amounts

Uptake Genes

• AHAo Extrudes H+ ions

• FRO2o Reduces Fe3+ → Fe2+

• IRT1o Transports Fe2+ into cell (regulated by ubiquitin)o Also involved in uptake of other heavy metal

cations

Transport Genes

• YSL1&2 o Influx (phloem)o Transport Fe-NA complexes

• FRD3 (MATE efflux family proteins)o Efflux (xylem)o Transport Fe-citrate complexes; provide shoots with

usable forms of Fe

Storage Genes

• Ferritino Complexes Fe2+ molecules togethero Stores readily-usable form of Fe in vacuoles &

amyloplasts

• PIC1o Transports Fe into chloroplasts

• IREG1o Moves Fe into vacuole

Regulatory Genes

• bHLH38,39,100&101o Regulate IRT1 and FRO2 genes

• FIT1o Forms heterodimers with bHLH → control

transcription of Fe uptake genes

• Both transcribed when Fe deficiency is sensed in the roots

QTLs

C01 1,923,307

C03 13,636,922

C05 43,302,017

C08 33,379,515

C09-1 3,558,943

C09-2 45,002,150

BLAST Results

C0

1QTL C01: 1,923,307

AHA1,2,9: 4,691,639*

IRT1: 3,007,445*

YSL2: 11,431,126*YSL1: 11,431,687

FIT1: 6,411,902*

0

+10,000,000

C0

3

-10,000,000

+10,000,000

AHA1,2,9: 19,835,760*

QTL C03: 13,636,922FRD3: 12,416,349*

FIT1: 16,455,349*

QTL

* = confirmed w/ IGBQuestionable presence on IGB

C0

5

-10,000,000

+10,000,000

AHA1,2,9: 43,882,387*

QTL C05: 43,302,017

IRT1: 41,537,794*

FRD3: 43,624,447*

FPN1/IREG1:34,728,143

FER1: 42,532,200*

FIT1: 39,453,920

C0

8

-10,000,000

+10,000,000

QTL C08: 33,379,515

AHA1,2,9: 32,394,505*

FRO1,2: 41,520,823*

IRT1:39,033,254*

FER1:30,370,173*bHLH38&39: 30,863,851*bHLH100&101: 30,878,266, 30,890,636*

QTL

* = confirmed w/ IGBQuestionable presence on IGB

C0

9

-10,000,000

+10,000,000

QTL C09-2: 45,002,150

AHA1,2,9:40,597,697*

IRT1: 49,050,708*

YSL1: 40,697,628

YSL2: 36,138,179*

QTL

* = confirmed w/ IGBQuestionable presence on IGB

QTL C09-1: 3,558,943

AHA1, AHA2: 514,992*

AHA9: 8,682,603*

FRO1: 137,473*

YSL1,2: 1,879,450*

PIC1: 7,315,088*

+10,000,000

0

C0

9

IGB Results

C0

1QTL C01: 1,923,307

2,114,850: Heavy metal transport/detoxification superfamily protein^

3,007,445 (ZIP9)^

-1,000,000

+1,000,000

QTLConfirmed BLAST resultGenes found only on IGB^ = gene identified through BLAST/TAIR method

● ZIP9 (homolog of IRT3)○ Location: nucleus, plasmodesma○ Expression: petal differentiation & expansion stage○ Function: transports zinc and other cations; contains

zinc/iron permease domain● Heavy metal transport/detoxification

superfamily protein○ Location: nucleus, plasmodesma○ Expression: petal differentiation and expansion stage○ Function: metal ion transport and binding

Confirmed BLAST resultGenes found only on IGB

C0

3QTL C03: 13,636,922

12,418,215: Multidrug resistance protein^

12,415,632: MATE efflux family protein (FRD3)^

-1,200,000

+1,200,000

QTLConfirmed BLAST resultGenes found only on IGB^ = gene identified through BLAST/TAIR method

• FRD3 (MATE efflux family protein)o Location: plasma membrane o Expression: petal differentiation & expansion stageo Function: iron-citrate transport

• MdtK (multidrug resistance protein)o Location: chloroplast & plasma membraneo Expression: petal differentiation & expansion stage o Function: ion transporter/antiporter activity

Confirmed BLAST resultGenes found only on IGB

C0

5QTL C05: 43,302,017

42,532,200: ferritin (FER1)^

42,731,745: Heavy metal transport/detoxification superfamily protein^

-1,000,000

+1,000,000

43,536,616: MATE efflux family protein (FRD3)^

43,624,447: MATE efflux family protein (FRD3)^

41,537,794: zinc transporter (IRT1)^

QTLConfirmed BLAST resultGenes found only on IGB^ = gene identified through BLAST/TAIR method

43,882,387: calcium transporting ATPase^

• IRT1o Location: membraneo Expression: petal differentiation & expansion stageo Function: cellular response to iron ion starvation, iron transport, etc.

• FER1o Location: chloroplasto Expression: petal differentiation & expansiono Function: iron ion transport and homeostasis, ferric iron binding

• Heavy metal transport/detoxification (homolog of ATX1)o Location: plasma membraneo Expression: pollen, petal, petioleo Function: metal ion transport & binding

• FRD3 (MATE efflux family protein)o Location: plasma membraneo Expression: roots, flower, petioleo Function: iron ion and citrate transport & homeostasis

Confirmed BLAST resultGenes found only on IGB

C0

8QTL C08: 33,379,515

32,394,505: H+-ATPase (AHA)

33,828,404: Ferrochelatase

-1,000,000

+1,000,000

QTLConfirmed BLAST resultGenes found only on IGB^ = gene identified through BLAST/TAIR method

• AHA (H+-ATPase)o Location: plasma membrane, Golgi apparatus,

vacuolar membraneo Expression: petal differentiation & expansiono Function: ion transport

• Ferrochelataseo Location: chloroplasto Expression: petal differentiation & expansiono Function: terminal enzyme of heme biosynthesis

Confirmed BLAST resultGenes found only on IGB

QTLConfirmed BLAST resultGenes found only on IGB^ = gene identified through BLAST/TAIR method

C0

9

QTL C09-1: 3,558,943

3,501,200: Ferrochelatase^

-1,000,000

+1,000,000

C0

9

-1,000,000

+1,000,000

QTL C09-2: 45,002,150

45,568,877: MATE efflux family protein

45,927,322: heavy metal transport/detoxification superfamily protein

QTLConfirmed BLAST resultGenes found only on IGB^ = gene identified through BLAST/TAIR method

• MATE efflux family protein o Location: (?)o Expressed in: (?)o Function: transport

• Heavy metal transport/detoxification superfamily proteino Location: extracellular space (?)o Expression: petal differentiation & expansiono Function: exact function unknown

Confirmed BLAST resultGenes found only on IGB

Conclusions

• IGB contained almost all genes found on BLAST

• Used IGB to confirm genes found on BLAST (+/- 1,000,000 bp)

• IGB yielded several new candidates (more speculative)

• Overall: a number of good candidate genes, close to QTL and expressed in relevant tissues

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