ROLE OF SULFUR IN PLANTS

NAME: MOHD SALEEMROLL NO: 14BTM28ENROL NO: GI3742CLASS: MSc. FINAL

MOHD SALEEMMSc Botany

Advanced plant physiology

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

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%

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.

Sulfur Assimilation

Sites of S assimilation in a cell

Physiological role of Sulfur4th 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

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

Continued…..• BiotinPyruvate carboxylase Acetyl CoA carboxylase

Role of Sulfur in stressBoth abiotic and biotic stresses

S-assimilation linked with antioxidant system under stress condition

Deficiency symptoms of Sulfur

Immobile Chlorosis in leaves – tea yellow diseaseLeaf tips and leaf margins roll inwardProtein synthesis – reducedInhibits nodule formationChlorophyll - protein complexes impaired

synthesisStem – hard

Deficiency symptoms

corn Tabacco

Stages of sulfur deficiency in Cannabis

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