Anatomy & Genetics - Paolo Flashcards
Tendrils and inflorescences are generally considered ________________ on the
basis of morphological, anatomical, and physiological similarities.
homologous
- similar in position, structure, and origin, but not in function. Same structural features and pattern of genes.
The individual flowers
on an inflorescence are _______________ with the separate floral organs originating from
___________________________.
modified shoots,
highly modified leaves
Flowers normally occur
in groups of
3 (triad) or
5 (dichasium)
How many flowers per cluster?
100-2000
Steps after flower fertilization:
- the embryo begins to form and
- the ovary wall thickens and begins to form the pericarp.
- the stigma has dried and soon the stamens will wither and drop.
A grape berry can have a
maximum of_____ seeds,
although in practice the seed
number is usually ________
four,
one or two
The ________forms the grape’s dermal system, or ‘skin’
exocarp
After the initial formation of the berry, what protects the it from water loss and pathogen invasions?
Epicuticular waxes cover the surface of the cuticle
forming a strongly hydrophobic layer
What is the berry mesocarp, how many cell layers does it have, and what is its purpose
The ‘flesh’ or ‘pulp’ of the grape berry, consists of 25 to 30 layers of thin-walled and highly vacuolated
storage parenchyma cells.
The vascular bundles that previously served the ovary
after berry-set give rise to
a complex network of vascular traces that supply the seed and the pericarp.
Describe the five main characteristics of the grapevine
-woody
-perennial (lives for several years)
-polycarpic (fruits for many years)
-deciduous (loses leaves)
-climber
What are the 4 main functions of the roots
-Physical support for the plant
- Water and nutrient uptake
- Storage organ of carbohydrates and nutrients
- Source of plant hormones (cytokinins, ABA)
What are the three main hormones in the roots and what is their purpose
Cytokinin: promotes cell division,cell growth, and cell differentiation.
Auxin: apical dominance and can influence gene expression
Absisic Acid: regulated stress responce, especially with water deficit
What is the phototropic response and what causes it
The phototropic response is when the plant moves in the direction of the sun. The plant growth hormone Auxin builds up on the shady side of the plant due to chemical transporters of Auxin are affected by sunlight.
In vegetatively propagated vines, primary roots originate from the ______________ of woody cuttings.
cambium layer
What are adventitious roots and where do they form
Plant roots that form from any nonroot tissue. They form near the nodes, but they also grow on the internodes. Occur durring normal development or a stress responce. Roots arising from wood cuttings.
The number and placement of roots depends on
The water and nutrient availability in the soil
Roots arising from wood cuttings are what type of roots
adventitious
Main roots develop from __________
whereas lateral/secondary roots develop from ____________
a directly cutting,
other roots
Lateral roots initiation happens where
in the unbranched apical zone and on older parts of the roots
Which is larger, the root system or the leaf canopy
root system
Where do the majority of the root grow
in the top 50 cm of soil
Which soil type will have higher root development and why? Clay or Sand
Sandy soils will cause the grapevine to grow more roots due to the fact that sand has a low water holding ability and the roots will constantly need to grow in order to find water
Compare the rooting depth of rootstocks V. riparia and V. rupestris
V. riparia roots are shallow (think river bed) while V. rupestris roots are deeper in the soil.
V. rupestris has a higher drought tolerance due to deeper roots.
Function of the root tip Elongation zone
cell expansion and differentiation
What tissue is in the root tip
meristematic tissue
What is the function of the root cap
Protects the tip, has gravity sensors, and produces polysaccharide-rich mucilage
What is the purpose of root exceted mucilage
The mucilage is a polysaccharide rich substance that feeds the mycellium fungi within the soil, contributing to their symbyotic relationship. The plant and the fungus exchange mucilage for nutrients and water
What are the two transmembrane pathways roots use to uptake water through the cells in the cortex (to get the water to the xylem). Explain them
The symplast and apoplast routes combine to form the transmembrane pathway.
Apoplast pathway - water moves through the spaces between the cells and in the cells walls themselves.
Symplast pathway - water flows between cells through plasmodesmata without crossing the plasma membrane.
What happens to the apoplast pathway at the endodermis?
The casparian strip blocks the apoplast pathway, forcing the water to move through the cell membrane and into the stele via the symplast pathway
What is mycorrhiza
a network that connects plants and fungi below ground and helps with nutrient and water uptake.
What forms the root vascular cambium and what are the main functions of the vascular cambium
Procambial cells develop into the vascular cambium, which retains its meristematic character and forms a continuous sleeve within the root-shoot axis
What is responsible for the formation of the secondary xylem, secondary phloem, and the radial growth of the roots
the vascular cambium
What causes cambium reactivation in the spring
root-derived cytokinin in response to auxin flowing down from the swelling buds.
What give roots their brownish color
The deposition of suberine in the cork cell walls and the oxidation of phenolics
Where is the cork cambium formed and what does it form
in the pericycle, which later forms
- cork toward the outside
- secondary cortex, phelloderm toward the inside
What are the functions of the trunk
-support for the growing vine
-water, nutrient, and assimilate transport
-storage organ for carbohydrates and nutrients
Because of its ___________, grapevines need
a training system (unless trained closed to the
ground)
liana nature
What are the types of pruning
-Spur pruning
-Cane pruning
What is a node
the point of insertion of lateral organs on the shoot
What is the difference between a grapevine seedling’s phyllotaxy compared to an adult grapevine’s phyllotaxy
The grapevine seedling’s (less than four leaves)
phyllotaxy is spiral (2/5), no tendrils
The adult grapevine has distic phyllotaxy (1/2), leaves opposite to tendrils/inflorescence
What is the phyllotaxy of primary shoots originating from buds
always 1/2 phyllotaxy
What are the two types of shoot growth, explain where they are formed
-fixed growth (leaf primordia pre-formed
during bud development and is responsible
for the rapid growth of the first 6-12 leaves)
-free growth (production of new leaf
primordia in the shoot’s apical meristem)
What is the pattern of shoot organs
-First 2-3 nodes usually only leaves
-Next 2 nodes generally clusters and leaves opposite
-Followed by 1 node with a leaf only
-Next two tendrils (possible cluster) with leaves opposite
-Followed by 1 node with leaf only
-Repeat tendrils & leaves, skipping every third
Which species of Vitis has a unique phyllotaxy with a tendrils and leaves always on the same side?
Vitis labrusca
The epidermis develops a ___________ on its outer cell walls as a protective layer of all above-ground organs.
waxy cuticle