Plant transcriptional regulators of abiotic stress

Abstract

The invention relates to plant transcription factor polypeptides, polynucleotides that encode them, homologs from a variety of plant species, and methods of using the polynucleotides and polypeptides to produce transgenic plants having advantageous properties compared to a reference plant, including improved abiotic stress tolerance. Sequence information related to these polynucleotides and polypeptides can also be used in bioinformatic search methods to identify related sequences and is also disclosed.

Description

RELATIONSHIP TO COPENDING APPLICATIONS [0001] This application claims the benefit of U.S. application Ser. No. 10 / 412,699, filed Apr. 10, 2003, which in turn claims the benefit of U.S. Non-provisional application Ser. No. 09 / 533,030, filed Mar. 22, 2000, which in turn claims the benefit of U.S. Provisional Application No. 60 / 125,814, filed Mar. 23, 1999, U.S. Non-provisional application Ser. No. 09 / 713,994, filed Nov. 16, 2000, which in turn claims the benefit of U.S. Provisional Application No. 60 / 166,228, filed Nov. 17, 1999, U.S. Provisional Application No. 60 / 197,899, filed Apr. 17, 2000, and U.S. Provisional Application No. 60 / 227,439, filed Aug. 22, 2000; U.S. Non-provisional application Ser. No. 10 / 112,887, filed Mar. 18, 2002; U.S. Non-provisional application Ser. No. 10 / 286,264, filed Jan. 23, 2003; U.S. Non-provisional application Ser. No. 10 / 225,068, filed Aug. 9, 2002; U.S. Non-provisional application Ser. No. 10 / 225,066, filed Aug. 9, 2002; U.S. Non-provisional applicat...

AI Technical Summary

Benefits of technology

[0045] The invention further pertains to an isolated nucleic acid comprising a nucleotide sequence at least 99.6% identical to

Problems solved by technology

Problems associated with drought.

A drought is a period of abnormally dry weather that persists long enough to produce a serious hydrologic imbalance (for example crop damage, water supply shortage, etc.).

In severe cases, drought can last for many years and can have devastating effects on agriculture and water supplies.

With burgeoning population and chronic shortage of available fresh water, drought is not only the number one weather related problem in agriculture, it also ranks as one of the major natural disasters of all time, causing not only economic damage, but also loss of human lives.

In some areas of the world, the effects of drought can be far more severe.

In the Horn of Africa the 1984-1985 drought led to a famine that killed 750,000 people.

Problems for plants caused by low water availability include mechanical stresses caused by the withdrawal of cellular water.

In addition to the many land regions of the world that are too arid for most if not all crop plants, overuse and over-utilization of available water is resulting in an increasing loss of agriculturally-usable land, a process which, in the extreme, results in desertification.

The problem is further compounded by increasing salt accumulation in soils, as described above, which adds to the loss of available water in soils.

Problems associated with high salt levels.

One in five hectares of irrigated land is damaged by salt, an important historical factor in the decline of ancient agrarian societies.

This condition is only expected to worsen, further reducing the availability of arable land and crop production, since none of the top five food crops—wheat, corn, rice, potatoes, and soybean—can tolerate excessive salt.

As with freezing and drought, high saline causes water deficit; the presence of high salt makes it difficult for plant roots to extract water from their environment (Buchanan et al.

In many parts of the world, sizable land areas are uncultivable due to naturally high soil salinity.

To compound the problem, salination of soils that are used for agricultural production is a significant and increasing problem in regions that rely heavily on agriculture.

The latter is compounded by over-utilization, over-fertilization and water shortage, typically caused by climatic change and the demands of increasing population.

Problems associated with excessive heat.

Seedlings and mature plants that are exposed to excess heat may experience heat shock, which may arise in various organs, including leaves and particularly fruit, when transpiration is insufficient to overcome heat stress.

Heat also damages cellular structures, including organelles and cytoskeleton, and impairs membrane function (Buchanan et al.

Heat stress often accompanies conditions of low water availability.

Heat itself is seen as an interacting stress and adds to the detrimental effects caused by water deficit conditions.

Evaporative demand exhibits near exponential increases with increases in daytime temperatures and can result in high transpiration rates and low plant water potentials (Hall et al.

High-temperature damage to pollen almost always occurs in conjunction with drought stress, and rarely occurs under well-watered conditions.

Thus, separating the effects of heat and drought stress on pollination is difficult.

Problems associated with excessive chilling conditions.

Most crops of tropical origins, such as soybean, rice, maize and cotton are easily damaged by chilling.

For example, chilling may lead to yield losses and lower product quality through the delayed ripening of maize.

Another consequence of poor growth is the rather poor ground cover of maize fields in spring, often resulting in soil erosion, increased occurrence of weeds, and reduced uptake of nutrients.

A retarded uptake of mineral nitrogen could also lead to increased losses of nitrate into the ground water.

Water deficit is a common component of many plant stresses.

Water deficit occurs in plant cells when the whole plant transpiration rate exceeds the water uptake.

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