01/06/2000 · Functional role of anthocyanins in the ..

Xanthophylls are structural components of the light harvesting antenna in chloroplasts.

Functional role of anthocyanins in the leaves of ..

What on earth is a “leggy”seedling?A leggy seedling is one with a root system, a loooong stem, and a fewleaves near the top. It is a result of growing in competition forlight or with inadequate light. Seedlings should be underat least 12 hours per day of light from the very first day they start toemerge and the light source should be less than 4 inches above the seedlings. At this point, they might be salvaged by transplanting to deep seedlingflats or pots so that the seed leaves are an inch or less above the soilline. You will have to be very careful, “leggy” seedlings are veryeasy to break. When you get ready to transplant outdoors, make atrench to plant them. Lay the stem out in the trench and prop theleaves up above the soil so they can grow. The plants will root allalong the stem which makes the plant more productive. See the infoabout lighting systems for info about bulbs and plant lights.

The ecophysiological function of anthocyanin has been ..

Seedlings should usually be transplanted after the last frost date foryour area. Contact your local agricultural extension office if youdon't know what that date is. Some general ranges are: zone 9 Februaryto early March, zone 8 March to early April, zone 7 late march to mid April,zone 6 mid to late April, zone 5 mid May. These are not absolutesand there will be years when tomatoes could be planted earlier and otheryears when cold temperatures will last longer than normal.

The one area where aluminum sulfate is recommended is in making blue hydrangeas blue. The chemistry of hydrangeas is such that not only acidity is necessary, but also aluminum ions are also necessary to make the flowers blue due to the aluminum binding with the anthocyanin. Hence, blue hydrangeas shouldn't share the same beds with rhododendrons and azaleas. Over application of aluminum sulfate can be toxic even to hydrangea.

23/09/2008 · Why do leaves change color and turn red

Zinc in the soil

The zinc content of unpolluted soils ranges between 10 – 80 mg kg-1 and the Zn content of sandy soils is generally lower than that of loamy soils. Freely available zinc in the soil solution binds mainly to the organic matter in the soil. In addition, it can be found adsorbed onto iron, manganese and aluminium oxides or strongly bound to the lattice of clay minerals and silicates. Additional immobilisation of zinc occurs when the sulphate and phosphate content in the soil solution are excessive. The availability of zinc is strongly affected by the pH and the total Zinc content of the soil. The proportion of exchangeable Zinc decreases with increasing pH and is already greatly reduced at pH 6. With increasing pH, the affinity of zinc to manganese oxide and iron oxide increases strongly. Under anaerobic conditions, zinc can be precipitated into the barely soluble sulphide form which is largely unavailable to plants Zinc can be leached from the soil but this process generally only occurs in acidic soils.

Zinc in the plant

Zinc is taken up by plants from the soil solution either as the Zn2+ ion (at low pH) or as the zinc hydroxide ion (at higher pH values). Plants grown in acid conditions of less than pH 6 are rarely short of Zinc since the availability under such conditions increases greatly. Zinc activates or is a component of several enzymes and therefore affects many metabolic processes in the plant.

Functions of zinc in the plant:

Zinc deficiency symptoms

Zinc toxicity

An excess of Zinc can be toxic in plants although the tolerance levels are usually high. Some plants are able to store surplus zinc in their vacuoles. Zinc toxicity results in:

water and sunlight into energy in a process called photosynthesis

Copper in the soil

The copper content of unpolluted soils typically ranges between 2-40 mg Cu kg-1 soil. Copper has a tendency to bind to the soil organic matter of the soil. It is adsorbed by manganese and iron oxides or it can be bound to the lattice silicates. In addition, it can precipitate as the hydroxide, carbonate or phosphate form. The concentration of copper in the soil solution depends on the pH value and the available chelating agents. The proportion of exchangeable copper generally increases with decreasing pH. Copper deficiency occurs on recently cultivated moorland soils and due to Cu fixation also in podsol soils rich in organic matter.

Copper in the plant

Plants take up Cu2+-ions freely from the soil solution or as soluble copper complexes. As a component of several enzymes, copper has a positive effect on the plant metabolism.

Function of copper in the plant

Copper deficiency

Copper excess

which is where the anthocyanin comes in

Boron in the soil

The boron content of soils in humid climates ranges between 5-80 mg kg-1. Soils rich in sand typically contain a lower boron content (5-20 mg kg-1) than soils rich in clay and organic matter (typically 30-80 mg kg-1). In saline soils, boron concentration may be so high that it can reach levels that are toxic to plants. Boron is present in the soil solution in the form of boric acid (H3BO3) which is produced during weathering of mica and tourmaline. Boric acid dissociates above pH 6.3 and the negative charge of the anion produced,is attracted to the positive surfaces of iron and aluminium oxide, clay minerals and organic substances thus limiting availability to the plant. Since boron is taken up with the soil water, boron deficiency mainly occurs during dry periods.

Boron in the plant

Boron belongs to the group of essential micro-nutrients and affects many processes in the plant metabolism. The requirement of the various crops for boron is very different. For example, monocotyledonous plants such as cereals generally have a lower requirement for boron than dicotyledonous crops. This is thought to be due to key differences in the cell wall structures of the two groups. Boron is taken up by plants mainly in the form of boric acid.

Functions of boron in the plant

Boron deficiency symptoms

Boron surplus in the plant