Introduction Introduction Salt stress Salt stress Osmotic stress - - PDF document

Oral Presentation CRDC 5 21/07/54 1 LOGO LOGO

Roles of silicon on growth Roles of silicon on growth of

• f

Thai Thai jasmine rice jasmine rice (Oryza Oryza sativa sativa L. cv. KDML

• L. cv. KDML105

105) ) under under salt stress salt stress

P t d b Ch kk L kkl Presented by Chakkree Lekklar Advisor: Dr. Anchalee Chaidee

Introduction Introduction

• Osmotic stress

Salt stress Salt stress

• Osmotic stress
• decreased water potential
• Oxidative stress
• reactive oxygen species

http://www.fao.org/DOCREP/

reactive oxygen species

• Ion toxicity
• [Na+], [Cl-]

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Silicon (Si) Silicon (Si) Silicon (Si) Silicon (Si)

• Beneficial element (Arnon and Stout, 1939)
• The difference in Si accumulation is dependent on

root uptake ability. (Ma and Takahashi, 2002)

• Si helps plants to overcome multiple stresses.

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• biotic stresses
• abiotic stresses
• Silicon induced disease resistance in rice.
• Silicon alleviated heavy metal toxicity.

Symptoms of sheath blight on six Brazilian of rice. (A) Control (0 g Si pot-1) and (B) plants grown at the highest rate of Si(1.92g Si pot-1) (Rodrigues et al, 2009) (Vaculík et al., 2009)

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• Silicon alleviated salt stress

Effects of Si on shoot and root dry weight (g/pot) of 10-day treatment cucumber plants grown in nutrient soln containing 0 or 50mM NaCl Effects of Si on shoot and root dry weight (g/pot) of 10-day treatment cucumber plants grown in nutrient soln containing 0 or 50mM NaCl (Zhu et al., 2004)

cultivar Shoot Na concentration (μmol g

• 1 weight)
• Si

+ Si Reduction (%) CRS 10 477±216 408±104 14.5 GR 4 866±131 314±147 63.7 IR 36 423±135 328±89 22.5

Effect of Si on shoot Na content of 3 cultivar of Oryza sativa L. grown for 7 d in culture soln salinized with NaCl (50 mM) Effect of Si on shoot Na content of 3 cultivar of Oryza sativa L. grown for 7 d in culture soln salinized with NaCl (50 mM) (Yeo et al., 1999)

Thai jasmine rice Thai jasmine rice

• Khao Dok Mali 105 (KDML 105)

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http://www.aftc.or.th/itc/products_analyze_price_01.php?id=56andfgrp_id=5andfmnu_id=18 http://negistda.kku.ac.th/research/research09/

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Objective Objective

To investigate roles of silicon on growth of Thai jasmine rice under salt stress To investigate roles of silicon on growth of Thai jasmine rice under salt stress Thai jasmine rice under salt stress Thai jasmine rice under salt stress

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http://www.nakorntonrice.com/images http://johnseconblog.files.wordpress.com

Materials and Methods Materials and Methods

3-week-old seedlings

Salt stress & Si treatments

• WP (Control)
• WP + 0.5 mM Si
• NaCl (60 mM)
• NaCl + 0 5 mM Si

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growth measurement (at 7 and 14 days) NaCl + 0.5 mM Si

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• Determination of photosynthetic pigments

Chlorophyll a Chlorophyll b C d

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Carotenoids

(Arnon, 1949)

Results Results Results Results and and Discussion Discussion

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Shoot fresh weight

1.335 0.355 0.752 0.630 0.553 0.745

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Day after treatment Root fresh weight

0.295 0.083 0.158 0.150 0.129 0.168

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Day after treatment

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Shoot dry weight

0.187 0.064 0.105 0.095 0.110 0.142

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Day after treatment Root dry weight

0.029 0.008 0.016 0.015 0.014 0.016

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Day after treatment

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Discussion Discussion

• Salt stress inhibited mass production of

KDML KDML105 rice.

• Relative water contents (RWC) did not

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change by salt stress.

• Si completely eliminated effect of salt

Discussion Discussion

stress on growth during 7 days.

• In prolonged salt stress (14 days), Si

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In prolonged salt stress (14 days), Si enhanced growth of shoot, but not root.

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Root/shoot ratio

• In KDML105 rice, salt stress

decreased root/shoot ratio decreased root/shoot ratio

• In general, salt stress

increases root/shoot ratio

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increases root/shoot ratio

Day after treatment

Chlorophyll a contents

3.18 2.78 1.64

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Day after treatment

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Chlorophyll b contents

1.09 0.96 0.56

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Day after treatment Carotenoid contents

1.15 0.9 0.53

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Day after treatment

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Discussion Discussion Pepper grown under drought stress

Chlorophyll a (a) and Chlorophyll b (b) in Capsicum annuum cv. Vermelho Gigante under the treatments control, 0.25 μM Si, 1.00 μM Si, 1.75 μM Si and stress.

(Lobato et al., 2009)

Discussion Discussion

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Effects of Si on chlorophyll a contents (A), chlorophyll b contents (B), carotenoid contents (C), total chlorophyll contents (D), chlorophyll a/b in cucumber leaves under Cd stress.

(Feng et al, 2010)

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Conclusion Conclusion

• Si alleviates salt stress by maintaining

photosynthetic pigment and shoot growth of KDML 105 rice.

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Further works Further works

• To examine effect of salt stress on induction
• f oxidative stress and antioxidant systems
• f oxidative stress and antioxidant systems
• To test whether Si-enhanced growth is

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associated with the activation of antioxidant systems under salt stress

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Acknowledgements Acknowledgements

• Higher Education Research Promotion and National Research

University Project of Thailand , Office of the Higher Education University Project of Thailand , Office of the Higher Education Commission

• Research Program on Conservation and Utilization of

Biodiversity and the Center of Excellence in Biodiversity, Faculty

• f Science, Chulalongkorn University

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• Environment and Plant Physiology Research Unit, Department of

Botany, Faculty of Science, Chulalongkorn University

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h k Thank you for your attention! attention!