Complex sentence: All the miRNAs in plants are derived from the sequential DCL1 cleavages from pri-miRNA to give pre-miRNA (or miRNA precursor), but the mirtrons bypass the DCL1 cleavage and enter as pre-miRNA in the miRNA maturation pathway.
Split into simpler sentences: All the miRNAs in plants are derived from the sequential DCL1 cleavages from pri-miRNA to give pre-miRNA (or miRNA precursor). But the mirtrons bypass the DCL1 cleavage and enter as pre-miRNA in the miRNA maturation pathway.