Two-way nitrogen transfer betweenDalbergia odorifera

and its hemiparasite Santalum albumis enhanced when the N2-fixing host

effectively fixes nitrogenXinhua He (xinhua.he@uwa.edu.au)

Centre of Excellence for Soil Biology, Southwest University,Chongqing 400715, China

School of Plant Biology, U. Western Australia, WA 6009, Australia

https://www.researchgate.net/profile/Xinhua_He3

Outerwood

●~15 years to mature●~8 m tall & 100 kg biomass (20 kg heartwood)/tree

Santalum: One of the most valuable timber tree

http://www.basenotes.net/features/1898-sandalwood-dreams-part-7

10K US$/tree or500 US$/kg

Sandalwood products as good as gold

http://www.sbs.com.au/news/article/2014/03/06/sandalwood-exports-good-gold

~5,000-15,000 US$

~$US5,000/kg or ~litre

● Traded for >300 years● Over-exploited● Banned in the Red List in 1992

Dalbergia nigra

Dalbergia: Another most valuable timber tree

Brazilian rosewood

Back side of a guitar(4,000 US$ for Brazilian rosewood)

A 16th Chinese MingDynasty compound

wardrobe made of Chinese'huanghuali' rosewood

More valuable Dalbergia rosewood

~20,000 US$

~500,000 US$!!!

https://en.wikipedia.org/wiki/Rosewood

● 600 years old

● 10 m length

● ~100 cm breastdiameter

●~3 tones

●US$ 30 million(1,000 US$/kg

or 1.0 US$/g)

The most expensive Dalbergia odorifera

http://news.hsw.cn/system/2014/1117/180250.shtml

Casuarina (~20-y old)

Acacia (6-y old)

Santalum (6-y old)

Acacia

Sandalwood on campus botanic gardenat University of Western Australia

A nightshiftshed

40-years-oldteak trees

StationOffice

(~150maway)？

？

Areinforcedconcrete

treeshelter in

2015

Barb wire

A concrete prisonor blockhouse?

A tree namelabel or anepitaph?

>1.0M RMB or ~0.2M US$ per Dalbergia odorifera

With non-N2-fixingBischofia polycarpa

With non-N2-fixingDracontomelonduperreranum

Without a host

With N2-fixing Acacia confusa With N2-fixing Dalbergia odorifera

2 mm

2 mm

2 mm

Nodules

Dalbergia

Acacia Acacia

Bischofia polycarp

Santalumhaustoria

Dalbergia odorifera: the best partner for sandalwoodgrowth comparing with other 3 paired plants and itself

●N2-fixation:~44% in Acacia confusa but ~50% in Dalbergia odorifera

● Leaf & root total N were significantly higher, while 15N weresignificantly lower in Santalum album

Lu et al. 2014. Tree Physiol 34: 1006

0.15% N (99.0 atom% 15N) leaf labeling

Lu et al. 2013. Tree Physiology 33: 464-74

Leaf

Ironwire

15N solution

Santalum albumDalbergia odorifera

Ironwire

99.0 at % 15N solution

Leaf

(a) Foliage

X Data

15

N v

alue

( ‰ )

-1

0

1

2

3

4

5

6 HostParasite

(b) Root

N2-fixing host-1

0

1

2

3

4

5

6

Non-N2-fixing host

, y

a, xb, x

, x

, x

b, ya, x

, y

b, x

a, x

, y

, x

d, x

, y

, x

c, x

Acacia/SantalumDalbergia/Santalum

Bischofia/Santalum

Dracontomelon/Santalum

Plan

td15N (‰

)(a) Foliage

X Data

15

N v

alue

( ‰ )

-1

0

1

2

3

4

5

6 HostParasite

(b) Root

N2-fixing host-1

0

1

2

3

4

5

6

Non-N2-fixing host

, y

a, xb, x

, x

, x

b, ya, x

, y

b, x

a, x

, y

, x

d, x

, y

, x

c, x

Acacia/SantalumDalbergia/Santalum

Bischofia/Santalum

Dracontomelon/Santalum

Partner or HostParasite

Aca

cia/

Sant

alum

Dalbergia/Santalum Lu et al. 2014. Tree

Physiology 34: 1006-17● ~50% N2-fixation

in Dalbergia

(a) Foliage

X Data

15

N v

alue

( ‰ )

-1

0

1

2

3

4

5

6 HostParasite

(b) Root

N2-fixing host-1

0

1

2

3

4

5

6

Non-N2-fixing host

, y

a, xb, x

, x

, x

b, ya, x

, y

b, x

a, x

, y

, x

d, x

, y

, x

c, x

Acacia/SantalumDalbergia/Santalum

Bischofia/Santalum

Dracontomelon/Santalum

Bischofia/Santalum

Dracontom

elon/Santalum

Non-N2-fixing partner

N2-fixing partner

Relationships between biomass production and N contentof 7-month-old Dalbergia () and Santalum () seedlings

nod+ or nod−:Inoculated ornon-inoculated

S+ or S−:Paired with

inoculated ornon-

inoculated D.odorifera

Lu et al. 2013. TreePhysiology 33: 464-74Nitrogen (mg/plant)

Biom

ass (

mg/

plan

t)

% of 2-way N transfer (A) & N in receivers derived fromtransfer (NDFT,B) in 7-m-old D. odorifera/S. album pairs

(a, b): between treatments for the same plant species(x, y): between species for a given treatment Lu et al. 2013. Tree Physiology 33: 464-74

Nitro

gen

trans

fers

(%)

NDFT

(%)

A B

Amount of 2-way N transfer (A) and net N transfer (B) in7-month-old D. odorifera/S. album pairs

A

(a, b): between treatments for the same plant species(x, y): between species for a given treatment Lu et al. 2013. Tree Physiology 33: 464-74

BNi

troge

n tra

nsfe

rs (m

g/pl

ant)

Net N

tran

sfers

(mg/

plan

t)

Non-nodulated

Nodulated

● Paired rosewoodnot only improvesthe growth ofsandalwood, butalso offers, itself,another high-valuewood to the worldmarket

●

7-year-old in south China

Sandalwood

Fragrantrosewood

●~50% N N2-fixationin Dalbergia odorifera● N2-fixation plays an

important role in N-translocation either tonon-N2-fixation or toN2-fixation partners

● Paired rosewood notonly improves the

growth ofsandalwood, but alsooffers, itself, anotherhigh-value wood tothe world market

7-Y-old insouth China

Sandalwood

Fragrantrosewood

Summary

Amount of N transfer (A) and net N transfer (B) in 7-month-old D. odorifera/S. album pairs

A B

(a, b): between treatments for the same plant species(x, y): between species for a given treatment Lu et al. 2013. Tree Physiology 33: 464-74

Acknowledgment● NSF China

● Chinese Academy of Forestry(JK Lu, Kang LH, DP Xu)

● UWA and U Sydney, Australia

● Janet Sprent, U Dundee, UK

● Stable Isotope Facility, UC Davis

● Southwest University, China xinhua.he@uwa.edu.auWelcome postgraduates, postdocs & staff, etc..

https://www.researchgate.net/profile/Xinhua_He3