What Is Acclimatization? Favorable environment for maximum growth
:
Interior : environment
high light, high nutrition, high water supply, high temperature low light, low relative humidity
The Two Sides of Acclimatization * Light Acclimatization * Soil Acclimatization reduce nutrient application, reduce water frequency. low light = less growth = less need for nutrients = less water need
Organ Level: Leaf
The Plant Leaf - An Overview of Structure upper epidermis palisade mesophyll chloroplasts spongy mesophyll vascular parenchyma xylem vascular tissues phloem stomates lower epidermis
Anatomical Differences Between 'Sun' and 'Shade' Plants
Organelle Level : Chloroplast Internal Organization High light chloroplast smaller chloroplasts less thylakoids / more stroma fewer grana stacks shorter smaller appressed areas less chlorophyll per volume
Low light chloroplast larger chloroplasts more thylakoids / less stroma more grana stacks taller, broader more chlorophyll per volume
The Chloroplast - An Overview of Structure
Structural and Physiological Differences Between 'Sun' and 'Shade' Plants
Changes in Natural Light Penetration Occur Within Interior Spaces Because of Changes in the Sun's Inclination Summer sun
Winter sun
General Characteristics of Sun and Shade Leaves Descriptive level Morphological
Sun leaves
leaves thicker
Shade leaves
often, a mosaic leaf arrangement, phototropic leaf petioles
General Characteristics of Sun and Shade Leaves Descriptive level
Sun leaves
more stomata Anatomical more palisade layers, longer cells, tighter packing
General Characteristics of Sun and Shade Leaves Descriptive level
Sun leaves
Shade leaves
larger chloroplasts, chloroplasts fewer and more grana, smaller grana phototactic chloroplasts
Ultrastructural smaller
General Characteristics of Sun and Shade Leaves Descriptive level Biochemical
Sun leaves
Shade leaves
lower chlorophyll a:b ratio high LCP high light saturation levels
more chlorophyll more chlorophyll b low respiration rates low LCP low light saturation levels
Differences Between Acclimatized And Non-acclimatized Plants Acclimatized Medium to dark green leaves Large leaves Flat leaves Thin leaves Leaves widely spaced
Non-acclimatized Yellowish to light green leaves Small leaves Partially folded leaves Thick leaves Leaves crowded together
Differences Between Acclimatized And Non-acclimatized Plants
Acclimatized Internodes long Thin to medium stems Leaf position horizontal or slightly reflexed Few new leaves Wide branch angles
Non-acclimatized Internodes short Thick stems Leaf position upright Many new leaves Acute angles
beginning of acclimatization: reorientation of chloroplast and grana; increase in chlorophyll levels; reduction in respiration rate; production of new foliage.
2 - 8 wks acclimatization complete
changes lead to lower compensation point
plant lives
changes do not lead to lower compensation point
plant dies
Time Required for Acclimatization ! Depends on species, plant size, previous treatment and magnitude of the change. 1 - 10 weeks or more; Examples:
Philodendron, Aglaonema - very little time required; Sun - grown Ficus benjamina and Brassaia in 40 to 80 % shade - approx. 5 wks; Ficus nitida in 50 % shade - 10 wks.
