Plant species are greatly differ in their sensitivity to heavy metals. Some plants are very sensitive to heavy metals but some other plants are withstand of heavy metals without much damage. Some plant species may thrive well on soil rich in heavy metals by avoiding uptake of heavy metals due to some normal selectivity of root cell membranes. this helps to identifing the metals which causes severe health issues to humans.

1. HEAVY METAL STRESS IN
PLANTS
BY SRIDHARSHINI.S
22MBO025
|-M.SC.,BOTANY

2. •Plant species are greatly differ
in their sensitivity to heavy
metals.
•Some plants are very sensitive
to heavy metals but some other
plants are withstand of heavy

3. WAYS OF PLANTS COPE WITH METALS
•It is in 2 ways
HEAVY METAL AVOIDANCE
HEAVY METAL TOLERANCE

4. HEAVY METAL AVOIDANCE
•Some plant species may thrive well on soil
rich in heavy metals by avoiding uptake of
heavy metals due to some normal
selectivity of root cell membranes.

5. HEAVY METAL TOLERANCE
•Some plant species absorb heavy metals
and accumulate them in their cell vacuoles
without much damage to a level that
would be lethal or sensitive or non-
tolerant species.
•Such plants are called accumulators or
super accumulators or heavy metal

6. • Nickel accumulators- excess absorb of dry by weight of >1000
mg.kg
Normal absorbion would be 0.05mg.kg
Eg., Talapsi goesingenese- 9.5mg/g (i.e.,1%)
FERNANDO et al recently discovered that, in Rinorea niccolifera
has >18000mg.kg in leaves without any poisoining.
Then it is commomly known as “nickel eating plants”.
These plants are greatly used in phytoremediation and
phytominig.
From plants prespective, Nickel-hyperaccumulating is a type of
defense from herbivores.

7. •Zinc accumulators and Lead accumulators
- e.g., Viola calaminaria excess of dry
weight >10,000mg.kg
•Selenium accumulators – excess
absorbtion of 10% of their dry weight.
Eg., Stanleya pinnata.

8. MECHANISM OF HEAVY METAL TOLERANCE
plants normally adapt 2 main strategy -
• 1.combination or complextion of toxic
heavy metals withorganic
compoundcompounds.
•2. compartmentation within the cell
vacuole

9. ORGANIC COMPOUNDS ARE USUALLY
PRODUCED BY PLANTS THAT CAPABLE OF
FORMING COMPLEXES WITH HEAVY METAL
•organic acidorganic - citrate and malate
combine with zinc and cadmium
•amino acids - histidine combine with
nickel
•phytochelates - sulphur rich metals
binding with poly peptides.

10. THANK YOU