In the world of plant tissue culture, cytokinins are the unsung heroes, playing a pivotal role in shoot multiplication. But not all cytokinins are created equal, as a recent study published in *Plants* reveals. The research, led by Anita Király from the Centre for Agricultural Genomics and Biotechnology at the University of Debrecen, Hungary, sheds light on how different cytokinins can significantly alter gene expression in in vitro apple shoots, with potential implications for the agriculture sector.
The study focused on two cytokinins: benzyl adenine (BA), a widely used synthetic cytokinin, and *meta*-topolin (mT), a naturally occurring cytokinin that has shown promise in improving shoot multiplication rates and quality. By employing mRNA sequencing and bioinformatics analysis, the researchers uncovered striking differences in how these two compounds influence gene expression.
“Our investigations revealed that benzyl adenine caused about six times more significantly up- or down-regulated genes than *meta*-topolin,” Király explained. This stark contrast suggests that mT might be a gentler, yet effective, alternative to BA, potentially reducing the risk of genetic instability in tissue-cultured plants.
The study also highlighted that both cytokinins affected the expression of key transcription factors, such as WRKYs, bHLH, and MYB. However, BA uniquely influenced the expression of MIKC-type MADS-box, ERF, and AP2 transcription factors, hinting at its broader, and potentially more disruptive, impact on plant physiology.
Moreover, the researchers found that BA and mT differentially affected genes related to auxin transport, signaling, and synthesis. Auxin, another crucial plant hormone, plays a significant role in plant growth and development. The study also revealed that BA uniquely up-regulated a gene encoding cytokinin hydroxylase-like protein, which is involved in the biosynthesis of *trans*-zeatin, a naturally occurring cytokinin. In contrast, a gene encoding gibberellin 20 oxidase 2-like, which is involved in gibberellin biosynthesis, was down-regulated after BA treatment but up-regulated after mT treatment.
These findings could have significant commercial impacts for the agriculture sector. By understanding how different cytokinins influence gene expression, researchers can develop more targeted and effective tissue culture protocols. This could lead to improved propagation of high-value crops, enhanced genetic stability in tissue-cultured plants, and more efficient use of plant growth regulators.
As the global demand for food continues to rise, the need for innovative and sustainable agricultural practices becomes ever more pressing. This research offers a promising avenue for exploration, with the potential to revolutionize plant tissue culture and contribute to food security.
Király’s work, published in *Plants*, underscores the importance of understanding the molecular mechanisms underlying plant growth and development. By unraveling the complex interplay between cytokinins and gene expression, researchers can pave the way for more efficient and sustainable agricultural practices, ultimately benefiting farmers and consumers alike.