Fig. 7.

Different causes of various dgd1 phenotypes. In dgd1 mutant plants, reduced digalactosyl diacylglycerol (DGDG) results in a dramatically increased monogalactosyl diacylglycerol (MGDG) : DGDG ratio, leading to jasmonic acid (JA) overproduction and consequently stunted growth characterized by short petioles and inflorescence stems. The rounded chloroplast phenotype may also be a result of the increased MGDG : DGDG ratio. Reduced photosynthesis and Chl content in the dgd1 mutant is most likely a direct consequence of DGDG insufficiency.