Phenotypic characterization of plants with altered expression of atwhy2. A. Four week old plants of the indicated genotypes grown in soil were photographed. B. Representative inflorescences and individual siliques taken from six week old plants of the indicated genotypes were photographed. C. Twenty individual mature siliques from the indicated genotypes were dissected and their average seed content was calculated. D. Equivalent leaves were taken from 6 week old plants and photographed. Leaves are ordered by age from left to right. E. Early accumulation of senescence marker transcripts in mature leaves of OEX plants. RT-PCR was performed on Col-0, KO and OEX RNA samples taken from the 3rd (L3) and 4th (L4) leaves of 5 week old plants using oligonucleotides designed to amplify specifically the following genes: At1g47128: Cystein protease RD21A, At2g45570: YLS6, Cell-death-associated cytochrome, At2g38860: YLS5, Protease I and At5g45890: SAG12, Cystein protease. Semi-quantitative conditions and primers for β-tubulin amplification were used to ensure adequate loading for all samples.