ROLE OF S IN PLANTS

1. NAME: MOHD SALEEM
ROLL NO: 14BTM28
ENROL NO: GI3742
CLASS: MSc. FINAL
MOHD SALEEM
MSc Botany
Advanced plant physiology

2. Contents
 sulfur general properties
 Sulfur cycle
 Source and available form
 Sulfur assimilation
 Role of sulfur
 Physiological role
 Catalytic role
 Role in stress
 Deficiency symptoms
 Toxicity symptoms

3. General Introduction Of Sulfur
Origin of the name Latin word “sulfurium’’
meaning Sulfur
Phase Solid.
Group, Period and Block 16, III, P
Atomic number 16
Relative atomic mass 32.066
Melting Point 115.21oC
Boiling Point 444.6 oC
Concentration in plants 0.05 – 1.5%

5. Source and available form of sulfur
 Occurs in both organic and inorganic forms.
 In soil S mainly occurs in minerals – pyrite,
cobaltite, gypsum, epsomite and in soluble form as
sulfate.
 Gaseous form of S : Sulfur oxides and hydrogen
sulfide.
 Mainly S is taken in the form of divalent anion sulfate
(SO4
2-).
 Through biological oxidation organic S is made
available to plants.
 Sulfate ions are reduced to sulphydryl group (-SH)
in plants.

6. Sulfur Assimilation

7. Sites of S assimilation in a cell

8. Physiological role of Sulfur
4th essential macronutrient after N, P &K. Group1
It is a constituent of :-
• Amino acids- Cysteine, Cystine and Methionine.
• Ferrodoxin.
• Volatile oils- Isothiocyanates and thiocyanates.
• S-adenosyl methionine (SAM).
• Sulfolipids.
• Vitamins- Thiamine, biotin and lipoic acid and
coenzyme A.
• Glutathione - GSH

9. Catalytic role of Sulfur
 Thiamine- TPP, lipoic acid and Co-A
 Pyruvate dehydrogenase complex enzyme(PDH)
 Oxoglutarate dehydrogenase etc.

10. Continued…..
• Biotin
Pyruvate carboxylase
Acetyl CoA carboxylase

11. Role of Sulfur in stress
Both abiotic and biotic stresses

12. S-assimilation linked with antioxidant
system under stress condition

13. Deficiency symptoms of Sulfur
Immobile
 Chlorosis in leaves – tea yellow disease
Leaf tips and leaf margins roll inward
Protein synthesis – reduced
Inhibits nodule formation
Chlorophyll - protein complexes impaired
synthesis
Stem – hard

14.  Deficiency symptoms
corn Tabacco

15. Stages of sulfur deficiency in Cannabis

17. Toxicity symptoms
• Rare
• Reduced leaf size and overall growth
• Yellowing of leaf or scorched at edges
• Induces deficiency to other nutrients by competition