Polynucleotides, polypeptides encoded thereby, and methods of using same for increasing abiotic stress tolerance and/or biomass and/or yield in plants expressing same

A method of selecting a plant having increased abiotic stress tolerance, seed yield, biomass, growth rate and/or nitrogen use efficiency as compared to a control plant of the same species which is grown under the same growth conditions, the method comprising:

• (a) providing plants transformed with a nucleic acid construct comprising a polynucleotide comprising a nucleic acid sequence encoding a polypeptide, wherein said polypeptide comprises the amino acid sequence set forth by SEQ ID NO:
• 271, and a heterologous promoter for directing transcription of said nucleic acid sequence in a plant cell, and;
• (b) selecting from said plants a plant having increased abiotic stress tolerance, seed yield, biomass, growth rate and/or nitrogen use efficiency as compared to a control plant of the same species which is grown under the same growth conditions, wherein the abiotic stress is selected from the group consisting of salinity stress and nitrogen deficiency, wherein when said abiotic stress is salinity stress then said tolerance to said salinity stress is an increase in said seed yield and/or an increase in said growth rate under salinity stress as compared to a native plant of the same species which is grown under the same growth conditions,
• thereby selecting the plant having increased abiotic stress tolerance, seed yield, biomass, growth rate and/or nitrogen use efficiency as compared to the control plant of the same species which is grown under the same growth conditions.

A method of increasing root length, root coverage, growth rate of rosette area, growth rate of rosette diameter, and/or increased seed yield of a plant as compared to the root length, root coverage, growth rate of rosette area, growth rate of rosette diameter, and/or seed yield of a control plant of the same species which is grown under the same growth conditions, comprising:

• (a) over-expressing within the plant a polypeptide comprising the amino acid sequence set forth by SEQ ID NO:
• 271, and
• (b) selecting from plants resultant of step (a) a plant exhibiting an increased root length, root coverage, growth rate of rosette area, growth rate of rosette diameter, and/or seed yield as compared to a control plant of the same species which is grown under the same growth conditions,
• thereby increasing the root length, root coverage, growth rate of rosette area, growth rate of rosette diameter, and/or seed yield of the plant as compared to the root length, root coverage, growth rate of rosette area, growth rate of rosette diameter, and/or seed yield of the control plant of the same species which is grown under the same growth conditions.

A method of selecting a plant having increased root length, root coverage, growth rate of rosette area, growth rate of rosette diameter, and/or seed yield as compared to a control plant of the same species which is grown under the same growth conditions, the method comprising:

• (a) providing plants transformed with a nucleic acid construct comprising a polynucleotide comprising a nucleic acid sequence encoding a polypeptide, wherein said polypeptide comprises the amino acid sequence set forth by SEQ ID NO:
• 271, and a heterologous promoter for directing transcription of said nucleic acid sequence in a plant cell, and;
• (b) selecting from said plants a plant having increased root length, root coverage, growth rate of rosette area, growth rate of rosette diameter, and/or seed yield as compared to a control plant of the same species which is grown under the same growth conditions,
• thereby selecting the plant having increased root length, root coverage, growth rate of rosette area, growth rate of rosette diameter, and/or seed yield as compared to the control plant of the same species which is grown under the same growth conditions.