Figure 1.

Ectopic overexpression of differently localized WHY1 isoforms in the why1 background. (a) Schematic constructs for 35S promoter-driven expression of WHY1 isoforms: pnWHY1, the full-length WHY1 coding sequence (CDS) plus an HA tag; nWHY1, the WHY1 CDS minus the plastid transit signal (PTS) plus the HA tag; and pWHY1, the full-length WHY1 CDS plus a nuclear export signal (NES) and the HA tag; (b) Western blot images showing subcellular (N: nucleus, P: plastids) accumulation of WHY1 isoforms in leaves of respective transgenic plants, using antibodies against the HA tag, histone H₂B, and cytochrome b559 (cytb559); (c) Left, statistic assessment of senescent leaves by color at the sixth week post-germination, error bars represent the SD for 30 plants each. Right, visualization of leaves of a typical plant at the same age, leaves were ordered by emergence; (d) Chlorophyll content and photosystem II fluorescence index (Fv/Fm) of the seventh rosette leaf measured after the fifth week post-germination. Error bars indicate the SD of five independent measurements.