pamiR: INVESTIGATING PLANT CELLS ONE ORGANELLE AT A TIME

pamiR, a plastid-focused artificial microRNA library, contains 2,285 guides targeting 2,202 plastid-enriched genes and enables organelle-specific forward genetic screening in plants.

• Why it matters: Conventional forward genetics is limited by functional redundancy and lacks organelle specificity, masking phenotypes in gene families and preventing precise identification of loci controlling plastid physiology.
• What they did: The library uses a constitutive UBQ10 promoter in binary vectors with a FAST seed-fluorescence marker, and two proof-of-concept screens used photosynthetic phenotyping and paclobutrazol to recover plastid-linked phenotypes.
• The result: Mass spectrometry confirmed paralogue-resolved LHCB1 depletion, KEA1 signal fell below immunoblot detection limit in pamiRkea1/2 and an independent KEA1/KEA2 line, and predicted off-target annotations were provided for all 2,285 guides.