Regulation of spikelet number during wheat spike development

Area of Science:

• Plant Science
• Agricultural Science
• Genetics

Background:

• Wheat inflorescences (spikes) are built from spikelets, and the spikelet number per spike (SNS) significantly impacts grain yield.
• Understanding the genetic regulation of SNS is crucial for improving wheat productivity.

Purpose of the Study:

• This review focuses on the gene networks controlling wheat spikelet development and SNS.
• To explore mechanisms that increase SNS and their implications for wheat breeding.

Main Methods:

• Review of existing literature on wheat spike development and genetics.
• Analysis of gene expression patterns, including spatial transcriptomics and single-cell studies.
• Examination of mutations affecting meristem identity and their impact on SNS.

Main Results:

• SNS is determined by the rate of spikelet meristem production and the timing of inflorescence meristem transition.
• Genes in the inflorescence meristem and florigen (FLOWERING LOCUS T1) transport influence SNS.
• Mutations can induce supernumerary spikelets or branches, but may have trade-offs with fertility and grain weight.

Conclusions:

• Identifying genes and alleles that increase SNS without negatively impacting other traits is advancing wheat breeding.
• Advanced molecular techniques are accelerating the discovery of genes controlling wheat spike architecture and yield potential.