Figure 5.

The combined deletion of SHM1 and SHM2 is detrimental. A, Top, shm1-1 × shm2-2 double mutant (white square on left image; enlarged in the right image) together with an shm1-1 homozygous plant (dotted circle) and a double-heterozygous plant after growth for 10 weeks in soil with 0.9% CO₂-enriched air. Bottom, A shm1-1 × shm2-2 double-homozygous individual after germination (left) and after growth for 8 weeks in 0.9% CO₂-containing air on MS medium with 1% Suc (right). B, RT-PCR confirms absence of SHM1 and SHM2 transcripts in leaves of four double-knockout lines (K2, K3, K4, and K9) in comparison with their presence in wild-type (WT) plants and the constitutively expressed S16 (At2g09990) transcripts used for internal calibration.