1. What the characteristics of an ideal drought tolerant crop plant could be?
Drought is considered as the most important environmental constraint affecting the plant growth and agricultural productivity worldwide. Climate change models predict drought to become worse. Drought stress could occur when the availability of water for plant is limited and the plant water demands exceed water supply. Many factors could lead to drought conditions, soil dryness, high evaporation, osmotic binding in saline soils, and inadequate water uptake by plant in the shallow soils. Under drought stress, susceptible plants would not be able to survive. The plants that will survive under this condition either escape (avoidance) or compete (tolerance) with drought stress. To improve drought tolerance in crops, the ideal plant must be able of acclimating drought stress by increasing survival rate, and at the same time maintaining high yield, by stabilizing the same level of photosynthesis under stress condition. Specifically by:
- Early sensing of the water deficit, which would help the plant to quickly respond to the upcoming stress and be ready to oppose to the drought stress.
- Quick response of water uptake by root, once faced drought condition by having more extensive root system (deeper roots and more lateral roots) (Yu et al., 2008).
- Reduce water loss such as low leaf stomatal density (Yu et al., 2008) and stomatal closure. Seeing that high water loss through leaf transpiration occurs at stomata, better control of transpirational water loss via the stomata could be key component of drought tolerance plant.
2. The molecular characteristics that ideal drought tolerance plant should have
Drought tolerance is a quantitative trait, many genes...
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...ly alert the plant by activating the drought-tolerance related gene NCED3. The expression of NCED3 will cause the increase in endogenous ABA level in root and leaves.
I) Accumulation of ABA and it effect on the root growth
ABA then activate transcriptional factor (TF), particularly in ABA dependent path, such as CBF4 (C-repeat binding factor4) or HDG11. Consequently, these TFs will active their target genes downstream e.g. LEA3 or P5CS gene. The activated LEA and P5CS will cause root grow deeper and more lateral roots, leading to drought tolerance in plant. (Figure 1)
II) Accumulation of ABA and its effect on stomatal closure
Accumulation of ABA in the leaf apoplast, leading to increased ABA at the guard cells to initiate closure and inhibits opening (Wilkinson and Davies 2002) through a physiological series of steps in response to water deficit (Figure1).
Carter, E., Theodorou, M., and Morris, P. 1997. Responses of lotus corniculatus to environmental Change I. effects of elevated CO2, temperature and drought on growth and plant development. New Phytologist. 136: 245-253.
Plasmolysis However when the plant cell is placed in a more concentrated solution the water inside the cell passes out the cell. The cytoplasm... ... middle of paper ... ...
As a result of these factors, the flora has adapted to these conditions in a variety of ways including their shape, leaf type, root system, and color. One of the most prominent adapt...
Plant hormones are certain chemicals present in plants that control plant growth and development by affecting the division, differentiation, and elongation of cells. (Campbell, 2008) Each hormone has multiple effects depending on its site of action, its concentrations, and the developing stage of the plant. (Campbell, 2008) Auxin is a plant hormone that is synthesized within the apical meristems and young leaves of a growing plant. Auxin stimulates stem elongation when it is present is low concentrations. It promotes the formations of lateral and adventitious roots, regulates development of fruit, enhances apical dominance, functions in gravitropism and phototropism, promotes vascular differentiation, and retards leaf abscission. Gibberellic acid is one of several plant hormones that govern a plant’s growth. Gibberellins allow for stem elongation in plants. Plants without enough of this hormone tend to grow short or stunted. This chemical is high in the element potassium, which is one the main components of plant fertilizer and very important for plant growth on its own. The...
With the rapid growth of our global population pouring into the next millennium, we will witness an ever-growing hunger rate around the world. That is unless we call for a revolution on the global scale. The Green Revolution which already sprouted in the early part of the century only need to add a bit more momentum and we will see a bright future for the human race, a future without hunger and starvation ¡V hopefully.It is becoming increasingly difficult for the planet to support its overwhelming population. And since the amount of arable land available is becoming scarce, we must seek ways to dramatically improve crop yields of existing cropland.
...hroughout the Eelgrass. Excess water in the form of vapor is disposed of through stomata on the leaves. The gas exchange, root, and shoot systems are used in this exchange because the stomata release the excess water in the form of water vapor, which was first absorbed by the roots in the root system, then transported through the xylem in the shoot system throughout the eelgrass. Another exchange that goes on in Eelgrass is nutrients to plant cells. Again the gas exchange, root, and shoot systems are used. Nutrients are absorbed by the roots and made through photosynthesis; stomata take in carbon dioxide which is used along with light, water, and other nutrients previously stored to make more. Nutrients are carried throughout the plant to plant cells by the phloem. Homeostasis is the balance of systems in organisms and it’s very important to keep them in balance.
How Light Affects the Stomatal Opening in a Leaf Abstract = == == ==
Aside from lignin’s obvious strengthening purpose it can also help plants in other ways. For instance, lignin contains specialized water conduct...
Drought escapers are the plants that “take advantage of favorable growing conditions when they exist but go dormant when those conditions disappear,” (NPS, Plants). These plants tend to be annuals, and if they have seeds produced within the favorable growing conditions, then these seeds can be dormant for multiple years. Most grasses and wildflowers within the area are normally drought escapers. Drought resistors, however, have processes and mechanisms to compensate for the drought (NPS, Plants). Some will “drop their leaves if water is unavailable” (NPS, Plants). A lot of drought resistors tend to have much smaller leaves to combat dehydration by decreasing the amount of direct sunlight and air exposure. Yuccas and mosses are two examples of drought resistors. In order to gather as much water as possible in a short amount of time, yuccas have large root systems that lie close to the surface. Mosses have tolerability to complete dehydration, and after rainfall, mosses will green up again (NPS,
own roots (not just the plant kind), this meant they needed a structure that was different than
How do plants resist being uprooted during typhoons? How do they absorb water? The answer lies on a particular plant structure, which is called the root. Basically, a monocot and a dicot root differ but also have common parts like the xylem and the phloem. Through examining the roots using the light microscope, the students would hopefully be able to understand how the root is designed to perform its vital functions. A root tip basically has 4 main regions, the root cap, the meristematic region, the region of cell elongation, and the region of cell differentiation. These parts are all essential for a root to function properly, thus further stressing its importance in t...
The tissue would gain in mass and length and will become turgid and sabotaging. If plant tissue has a higher water potential than
The strong cells wall prevents bursting. The cell is turgid. If plant cells lose water the cells become limp and flaccid. Water is essential for support in plants.
Genetic engineering enhances plant resistance to drought, salinity, disease, pests and herbicides. The aim is to try and enhance the growth, productivity, nutrient value, and chemical composition of the plants. Chemicals are constantly being developed or improved to enhance the competitiveness and adaptability of crops, and to kill the parasites and weeds which plague the agricultural sector. . This however is not always good as the plant and the pests then become resistant to these new chemicals defeating the purpose of it being used. The new chemicals which are produced to kill these strong pests and weeds may be more harmful to other plants and remove nutrients within the soil in turn reducing the yield of agricultural crops. The benefits of these characteristics are seen in Argentina according to Pelletier (2010) as they use glyphosphate resistant soybean which allowed the comeback of this crop, as the so...
Global warming is one of the main causes, which leads to the lack of water and drought. A drought-like condition exists in most of India’s part. Government of India states that 68% of the country is disposed to the drought, which (consequences are) leads to massive migration of people to more favorable places, famine, conflicts among inhabitants. India is known in the world as one of the biggest producers of water-intensive crops such as rice, sugarcane and wheat. According to a survey done by Grail Research, approximately 82% of total water is used for agricultural consumption and 90% of it is employed for irrigation of rice, wheat and sugarcane (Grail Research, LLC, 2009). There are several solutions which could lead to the decr...