investigating the effects of plant hormones on the growth of a.niger

Investigating the effects of Plant Hormones on the growth

of A.Niger

PRESERVATIVE?

Objectives• Investigate the ability of different plant hormones

(or a mixture) to defend tomatoes from fungus Aspergillus niger

• Way to increase the storage time of tomatoes

• Why A.niger?Inflicts tremendous damage to

plants and crops

Infects dead, dying or injured plant tissues

Introduction

Known as Black Mould

Affects certain fruits and vegetables

Inflicts damage on dead and injured plant tissues

Introduction

Organic substances

Causes physiological responses

Target audience

• Farmers who grow tomatoes

• People who want to keep their tomatoes for a longer time

• People who want to find out how to reduce mould growth on tomatoes

Hypothesis

The plant hormone that best impedes the growth of Aspergillus Niger is salicylic acid.

Variables

Independent Type of Plant

Hormones

DependentDecrease in mass

ControlType of fruit usedAmount of A.nigerAmount of plant

hormonesDays for A.niger to infect the tomato

MaterialsAspergillus niger

Methyl Jasmonate

Salicylic acid

Kinetin Syringe

Tomatoes

Potato dextrose broth

Potato dextrose agar

Electronic Balance Petri dishes

Methodology

•We culture the Aspergillus niger onto potato Dextrose Broth for 2 days

•We put the tomatoes onto sterile petri-dishes and labelled the petri-dishes according to the hormones we would inject into the respective tomatoes. The hormones we injected were salicylic acid, kinetin and methyl jasmonate.

Methodology• We injected the plant hormones into

the tomatoes. The concentration of the plant hormones we added were 30 microlitres/ml. We injected 1ml of hormones into the tomatoes.

• For the control set-up, we injected 1ml of water into the tomatoes

• We injected 0.5 ml of the Aspergillus niger solution (mixed in potato dextrose broth solution into the tomatoes). We measured the mass of the tomatoes during the following intervals:– Start of experiment– 2 hours later– 1 day later– 2 days later

Methodology

Methodology

Salicylic acid Methyl Jasmonate Kinetin

Salicylic acid +Methyl Jasmonate

Salicylic acid + Kinetin

Methyl Jasmonate + Kinetin

All three hormones Control

Factor used to measure the extent of decay

• Mass of the tomatoes

Overview of results

S M K S+M S+K M+K S+K+M Control0

10

20

30

40

50

60

70

80

Mass of tomatoes in set-up 1

Day 02 hours laterDay 1Day 2

Types of plant hormones used

Mas

s of

tom

atoe

s/g

Mass of tomatoes (set-up 1)

S M K S+M S+K M+K S+K+M Control0

10

20

30

40

50

60

70

80

Mass of tomatoes in set-up 2

Day 02 hours laterDay 1Day 2

Types of plant hormones used

Mas

s of

tom

atoe

s/g

Mass of tomatoes (set-up 2)

S M K S+M S+K M+K S+K+M Control0

10

20

30

40

50

60

70

80

90

Mass of tomatoes in set-up 3

Day 02 hours laterDay 1Day 2

Types of plant hormones used

Mas

s of

tom

atoe

s/g

Mass of tomatoes (set-up 3)

S M K S+M S+K M+K S+K+M Control0

0.5

1

1.5

2

2.5

3

3.5

4

Percentage decrease in mass of tomatoes in Set-up 1

Series1

Hormones injected

Perc

enta

ge d

ecre

ase

in m

ass/

%

Percentage decrease in mass of tomatoes (set-up 1)

S M K S+M S+K M+K S+K+M Control0

0.5

1

1.5

2

2.5

3

3.5

Percentage decrease in mass of tomatoes in Set-up 2

Series1

Hormones injected

Perc

enta

ge d

ecre

ase

in m

ass/

%

Percentage decrease in mass of tomatoes (set-up 2)

Percentage decrease in mass of tomatoes (set-up 3)

S M K S+M S+K M+K S+K+M Control0

0.5

1

1.5

2

2.5

3

3.5

4

Percentage decrease in mass of tomatoes in Set-up 3

Series1

Hormones injected

Perc

enta

ge d

ecre

ase

in m

ass/

%

S M K S+M S+K M+K S+K+M Control2.5

2.6

2.7

2.8

2.9

3

3.1

3.2

3.3

Average percentage decrease in mass of tomatoes for the 3 set-ups

Series1

Hormones injected

Perc

enta

ge d

ecre

ase

in m

ass/

%

Average percentage decrease in mass

Raw DataHormone % decrease in mass

SA 2.746480022MJ 3.114938598KI 2.84314562

SA + MJ 3.170528505SA + KI 2.843008458MJ + KI 2.858655563

SA + MJ + KI 3.025592654Control 2.935635524

General analysis of results• The mass of the tomatoes which were injected

with salicylic acid decreased the least• Among the three hormones, salicylic acid works

best at impeding growth of Aspergillus Niger, followed by kinetin, and then Methyl Jasmonate

Salicylic acidSalicylic acid + KinetinKinetin

Methyl Jasmonate + Kinetin

ControlAll 3 hormonesSalicylic acid + Methyl Jasmonate

Methyl Jasmonate

Impedes growth of Aspergillus Niger the most

Impedes growth of Aspergillus Niger the least

General analysis of results

Explanation of results – salicylic acid

Salicylic acid •“Attacks” the invading pathogen itself•Is harmful to pathogens due to its acidic nature

Kinetin•Stimulates tRNA (transfer RNA) synthesis•Protects plant cells against stress by suppressing cell death by viruses and toxic chemicals•Acts as a preservative

Methyl Jasmonate •Induces the plant to produce multiple different types of defence chemicals.

Limitations

• We originally intended to use jasmonate acid instead of kinetin. However, jasmonate acid is too expensive and the SRC cannot afford it. Hence, we found a replaced jasmonate acid with kinetin

• Using plant hormones as a form of “preservative” for the tomatoes would cost a lot as the hormones are expensive

Conclusion

• Salicylic acid works best on impeding growth of Aspergillus Niger among the three plant hormones used in the experiment

Benefits

• Injecting plant hormones is more environmentally friendly than using fungicides. Unlike fungicides, plant hormones are not toxic to humans and wildlife.

• The fruits injected with this hormones may not be suitable for consumption, and hence this method may not be applicable for agricultural purposes.

Applications

• Salicylic acid can be injected into fruits like tomatoes to reduce the Aspergillus Niger growth on the fruits. This increases the storage time of fruits.

Bibliography• http://www.crscientific.com/article-aspirin.html

From CR Scientific LLC (date not applicable)• http://onlinelibrary.wiley.com/doi/10.1002/pca.1085/abstract • Written Feng Juan Zhang, You Ju Jin, Xing You Xu, Rong Chun Lu,• Hua Jun Chen (10 JUL 2008)• http://www.cliffsnotes.com/study_guide/Types-of-Plant-Hormones.topicArticleId-

23791,articleId-23713.html#ixzz1AAQ3pfpI

• From Cliffnotes.com (4 Apr 2011) • http://www.brighthub.com/health/conditions-treatments/articles/9543.aspx • Written by user MandaSpring (1 Oct 2008)• http://www.gardenguides.com/132402-aspergillus-niger-structure.html • Written by Sarah Terry (date not applicable)

Bibliography• http://

www.biog1105-1106.org/demos/105/unit5/media/plantdefensehormones.pdf• http://www.chm.bris.ac.uk/motm/jasmine/jasminev.htm• http://

www.sureshrattan.com/index.php?option=com_content&view=article&id=48&Itemid=68

• http://www.cliffsnotes.com/study_guide/Types-of-Plant-Hormones.topicArticleId-23791,articleId-23713.html#ixzz1AAQ3pfpI

• http://www.apsnet.org/edcenter/intropp/topics/Pages/OverviewOfPlantDiseases.aspx

• Google Images• Presentation magazine

Thank You