Figure 7.

Unlike (a) Wild Type Arabidopsis seeds, (b) mutant seed maturation protein1 (smp1) seeds lose the capacity to enter thermo-dormancy (invoked by 4 days at 42 °C while hydrated (blue pool of water)) when subsequently removed to a permissive temperature, 25 °C. The soybean LEAP GLYCINE MAX PHYSIOLOGICAL MATURE 28 (GmPM28) and its Arabidopsis orthologue, SMP1, were both able to bind several of the same client proteins. The protein most frequently bound by both orthologs was the CANCER SUSCEPTIBILITY CANDIDATE3 (CASC3), capable of marking the splice junction on mature mRNA and enhancing translation. Presumably, loss of the LEAP destabilized CASC3 during high-temperature stress and this may lead to the inability of a (presumably repressive) protein to subsequently exert thermo-dormancy on a sub-population of the seeds.