Project description:Meristems are highly regulated structures ultimately responsible for the formation of branches, lateral organs, and stems, and thus directly affect plant architecture and crop yield. In meristems, genetic networks, hormones, and signaling molecules are tightly integrated to establish robust systems that can adapt growth to continuous inputs from the environment. Here we characterized needle1 (ndl1), a temperature-sensitive maize mutant that displays severe reproductive defects and strong genetic interactions with known mutants affected in the regulation of the plant hormone auxin. NDL1 encodes a mitochondria-localized ATP-dependent metalloprotease belonging to the FILAMENTATION TEMPERATURE-SENSITIVE H (FTSH) family. Together with the hyperaccumulation of reactive oxygen species (ROS), ndl1 inflorescences show up-regulation of a plethora of stress-response genes. We provide evidence that these conditions alter endogenous auxin levels and disrupt primordia initiation in meristems. These findings connect meristem redox status and auxin in the control of maize growth.
Project description:Gene expression in response to severe heat stress (50°C 1 h) was compared between thermotolerant and thermosensitive tomato cultivars. The thermosensitive cultivar showed severe impairment of heat stress response at this condition, while the thermotolerant cultivar were less affected. The results of this experiment were used to select expression marker genes that reflect the cellular heat shock response and correlate with thermotolerance.