ZmDRR206 Regulates Nutrient Accumulation in Endosperm through Its Role in Cell Wall Biogenesis during Maize Kernel...

Area of Science:

• Plant Biology
• Molecular Genetics
• Agricultural Science

Background:

• Dirigent proteins (DIRs) are crucial for plant cell wall dynamics and defense.
• ZmDRR206, a maize DIR, is known for roles in seedling growth and defense but its function in kernel development was unclear.

Purpose of the Study:

• To investigate the role of ZmDRR206 in maize kernel development and its association with hundred-kernel weight (HKW).

Main Methods:

• Association analysis of ZmDRR206 variations with HKW.
• Overexpression of ZmDRR206 in maize.
• Cytological characterization of developing kernels.
• Gene expression analysis of BETL, auxin, and cell wall-related genes.

Main Results:

• ZmDRR206 variations are significantly associated with maize HKW.
• ZmDRR206 overexpression leads to smaller kernels with reduced starch and HKW.
• Dysfunctional basal endosperm transfer layer (BETL) cells and constitutive defense responses were observed in overexpressing kernels.
• Down-regulation of BETL and auxin-related genes, alongside up-regulation of cell wall biogenesis genes, occurred in developing BETL.

Conclusions:

• ZmDRR206 plays a key regulatory role in maize kernel development, impacting cell development, nutrient metabolism, and stress responses.
• Its function involves cell wall biogenesis and defense mechanisms, offering insights into maize kernel development and yield improvement.