Coincidence of potato CONSTANS (StCOL1) expression and light cannot explain night-break repression of tuberization

Identification of BBX gene family and its function in the regulation of microtuber formation in yam

BBX proteins play important roles in all of the major light-regulated developmental processes. However, no systematic analysis of BBX gene family regarding the regulation of photoperiodic microtuber formation has been previously performed in yam. In this study, a systematic analysis on the BBX gene family was conducted in three yam species, with the results, indicating that this gene plays a role in regulating photoperiodic microtuber formation. These analyses included identification the BBX gene family in three yam species, their evolutionary relationships, conserved domains, motifs, gene structure, cis-acting elements, and expressional patterns. Based on these analyses, DoBBX2/DoCOL5 and DoBBX8/DoCOL8 showing the most opposite pattern of expression during microtuber formation were selected as candidate genes for further investigation. Gene expression analysis showed DoBBX2/DoCOL5 and DoBBX8/DoCOL8 were highest expressed in leaves and exhibited photoperiod responsive expression patterns. Besides, the overexpression of DoBBX2/DoCOL5 and DoBBX8/DoCOL8 in potato accelerated tuber formation under short-day (SD) conditions, whereas only the overexpression of DoBBX8/DoCOL8 enhanced the accelerating effect of dark conditions on tuber induction. Tuber number was increased in DoBBX8/DoCOL8 overexpressing plants under dark, as well as in DoBBX2/DoCOL5 overexpressing plants under SD. Overall, the data generated in this study may form the basis of future functional characterizations of BBX genes in yam, especially regarding their regulation of microtuber formation via the photoperiodic response pathway.

Genome-Wide Identification, Characterization and Expression Profiling of the CONSTANS-like Genes in Potato (Solanum tuberosum L.)

CONSTANS-like (COL) genes play important regulatory roles in flowering, tuber formation and the development of the potato (Solanum tuberosum L.). However, the COL gene family in S. tuberosum has not been systematically identified, restricting our knowledge of the function of these genes in S. tuberosum. In our study, we identified 14 COL genes, which were unequally distributed among eight chromosomes. These genes were classified into three groups based on differences in gene structure characteristics. The COL proteins of S. tuberosum and Solanum lycopersicum were closely related and showed high levels of similarity in a phylogenetic tree. Gene and protein structure analysis revealed similarities in the exon-intron structure and length, as well as the motif structure of COL proteins in the same subgroup. We identified 17 orthologous COL gene pairs between S. tuberosum and S. lycopersicum. Selection pressure analysis showed that the evolution rate of COL homologs is controlled by purification selection in Arabidopsis, S. tuberosum and S. lycopersicum. StCOL genes showed different tissue-specific expression patterns. StCOL5 and StCOL8 were highly expressed specifically in the leaves of plantlets. StCOL6, StCOL10 and StCOL14 were highly expressed in flowers. Tissue-specific expression characteristics suggest a functional differentiation of StCOL genes during evolution. Cis-element analysis revealed that the StCOL promoters contain several regulatory elements for hormone, light and stress signals. Our results provide a theoretical basis for the understanding of the in-depth mechanism of COL genes in regulating the flowering time and tuber development in S. tuberosum.

New Horizons in Plant Photoperiodism

Photoperiod-measuring mechanisms allow organisms to anticipate seasonal changes to align reproduction and growth with appropriate times of the year. This review provides historical and modern context to studies of plant photoperiodism. We describe how studies of photoperiodic flowering in plants led to the first theoretical models of photoperiod-measuring mechanisms in any organism. We discuss how more recent molecular genetic studies in Arabidopsis and rice have revisited these concepts. We then discuss how photoperiod transcriptomics provides new lessons about photoperiodic gene regulatory networks and the discovery of noncanonical photoperiod-measuring systems housed in metabolic networks of plants. This leads to an examination of nonflowering developmental processes controlled by photoperiod, including metabolism and growth. Finally, we highlight the importance of understanding photoperiodism in the context of climate change, delving into the rapid latitudinal migration of plant species and the potential role of photoperiod-measuring systems in generating photic barriers during migration.

From crops to shops: how agriculture can use circadian clocks

Knowledge about environmental and biological rhythms can lead to more sustainable agriculture in a climate crisis and resource scarcity scenario. When rhythms are considered, more efficient and cost-effective management practices can be designed for food production. The circadian clock is used to anticipate daily and seasonal changes, organize the metabolism during the day, integrate internal and external signals, and optimize interaction with other organisms. Plants with a circadian clock in synchrony with the environment are more productive and use fewer resources. In medicine, chronotherapy is used to increase drug efficacy, reduce toxicity, and understand the health effects of circadian clock disruption. Here, I show evidence of why circadian biology can be helpful in agriculture. However, as evidence is scattered among many areas, they frequently lack field testing, integrate poorly with other rhythms, or suffer inconsistent results. These problems can be mitigated if researchers of different areas start collaborating under a new study area-circadian agriculture.