Arabidopsis thaliana Transcriptome or Gene expression

The nuclear lamina (NL) is a complex network of nuclear lamins and lamin-associated nuclear membrane proteins, which scaffold the nucleus to maintain structural integrity. In Arabidopsis thaliana, Nuclear Matrix Constituent Proteins (NMCPs) are essential components of the NL and are required for maintaining the structural integrity of the nucleus and specific perinuclear chromatin anchoring. At a chromosomal level, plant chromatin organization in interphase nuclei displays flexibilities. Many developmental cues and environmental factors, such as dedifferentiation, leaf development, seedling growth, floral transition, seed development, light intensity, microbe infection, and temperature stress, can trigger global rearrangement of chromatin, demonstrating a tight connection between the structural arrangement of chromatin and its activities. Based on these observations from Arabidopsis, and given the role of AtNMCP genes (i.e., CRWN1 and CRWN4) in organizing chromatin positioning at the nuclear periphery, one can expect considerable changes in chromatin-NL interactions when the global chromatin organization patterns are being altered in plants. Here, we show that plant nuclear lamina disassembles substantially under various stress conditions. Focusing on heat stress, we revealed that chromatin domains, initially tethered to the nuclear envelope, remained largely associated with CRWN1 and became scattered in the inner nuclear space. We further show that CRWN1 proteins function as negative factors during heat stress to prevent repressed chromatin from being over-decondensed. Also, CRWN1 acts as a negative transcriptional co-regulator to modulate the shift of the plant transcriptome profile in response to heat stress.