Transgenerational Paternal Inheritance of ITaCKX/I GFMs Expression Patterns Indicate a Way to Select Wheat Lines with Better Parameters for Yield-Related Traits

• Published in: International journal of molecular sciences Vol. 24; no. 9
• Main Authors: Szala, Karolina, Dmochowska-Boguta, Marta, Bocian, Joanna, Orczyk, Waclaw, Nadolska-Orczyk, Anna
• Format: Journal Article
• Language: English
• Published: MDPI AG 01.05.2023
• Subjects: Genes; Genomics; Wheat
• ISSN: 1422-0067; 1422-0067
• DOI: 10.3390/ijms24098196

Members of the TaCKX gene family (GFMs) encode the cytokinin oxygenase/dehydrogenase enzyme (CKX), which irreversibly degrades cytokinins in the organs of wheat plants; therefore, these genes perform a key role in the regulation of yield-related traits. The purpose of the investigation was to determine how expression patterns of these genes, together with the transcription factor-encoding gene TaNAC2-5A, and yield-related traits are inherited to apply this knowledge to speed up breeding processes. The traits were tested in 7 days after pollination (DAP) spikes and seedling roots of maternal and paternal parents and their F[sub.2] progeny. The expression levels of most of them and the yield were inherited in F[sub.2] from the paternal parent. Some pairs or groups of genes cooperated, and some showed opposite functions. Models of up- or down-regulation of TaCKX GFMs and TaNAC2-5A in low-yielding maternal plants crossed with higher-yielding paternal plants and their high-yielding F[sub.2] progeny reproduced gene expression and yield of the paternal parent. The correlation coefficients between TaCKX GFMs, TaNAC2-5A, and yield-related traits in high-yielding F[sub.2] progeny indicated which of these genes were specifically correlated with individual yield-related traits. The most common was expressed in 7 DAP spikes TaCKX2.1, which positively correlated with grain number, grain yield, spike number, and spike length, and seedling root mass. The expression levels of TaCKX1 or TaNAC2-5A in the seedling roots were negatively correlated with these traits. In contrast, the thousand grain weight (TGW) was negatively regulated by TaCKX2.2.2, TaCKX2.1, and TaCKX10 in 7 DAP spikes but positively correlated with TaCKX10 and TaNAC2-5A in seedling roots. Transmission of TaCKX GFMs and TaNAC2-5A expression patterns and yield-related traits from parents to the F[sub.2] generation indicate their paternal imprinting. These newly shown data of nonmendelian epigenetic inheritance shed new light on crossing strategies to obtain a high-yielding F[sub.2] generation.