Transcriptome Analysis of Flowering Time Genes under Drought Stress in Maize Leaves

Abstract

Flowering time is an important factor determining yield and seed quality in maize. A change in flowering time is a strategy used to survive abiotic stresses. Among abiotic stresses, drought can increase anthesis-silking intervals (ASI), resulting in negative effects on maize yield. We have analyzed the correlation between flowering time and drought stress using RNA-seq and bioinformatics tools. Our results identified a total of 619 genes and 126 transcripts whose expression was altered by drought stress in the maize B73 leaves under short-day condition. Among drought responsive genes, we also identified 20 genes involved in flowering times. Gene Ontology (GO) enrichment analysis was used to predict the functions of the drought-responsive genes and transcripts. GO categories related to flowering time included reproduction, flower development, pollen–pistil interaction, and post-embryonic development. Transcript levels of several genes that have previously been shown to affect flowering time, such as PRR37, transcription factor HY5, and CONSTANS, were significantly altered by drought conditions. Furthermore, we also identified several drought-responsive transcripts containing C2H2 zinc finger, CCCH, and NAC domains, which are frequently involved in transcriptional regulation and may thus have potential to alter gene expression programs to change maize flowering time. Overall, our results provide a genome-wide analysis of differentially expressed genes (DEGs), novel transcripts, and isoform variants expressed during the reproductive stage of maize plants subjected to drought stress and short-day condition. Further characterization of the drought-responsive transcripts identified in this study has the potential to advance our understanding of the mechanisms that regulate flowering time under drought stress.

Complex interactions between day length and diurnal patterns of gene expression drive photoperiodic responses in a perennial C4 grass

“…Interestingly, evidence has continued to grow in support of crosstalk between photoperiodic flowering pathways and diverse signalling in complex environments, including the temperature and abiotic stress (Riboni et al, ; Song et al, ). Unfortunately, a large number of prior studies have ignored the importance of sampling time, especially in transcriptome analysis in various stress response studies (Li, Wang, Tang, Kakani, & Mahalingam, ; Miao, Han, Zhang, Chen, & Ma, ; Song et al, ; Tang et al, ; Wang et al, ). Our finding suggest that a time‐series experiment design will help to avoid this bias in future gene‐by‐environment research (Lovell, Shakirov, et al, ).…”

A systems genetics approach reveals environment-dependent associations between SNPs, protein co-expression and drought-related traits in maize

“…Second, on chromosome 5, we identified a QTL for Trate which co-localized with a pQTL associated to the ZmRab17 dehydrin in the WD condition. Among the six genes underlying both the QTL and the pQTL is the transcription factor ZmWRKY48 (GRMZM2G120320), which has been shown to be induced by water deficit (Song et al 2017). This gene is orthologous to AtWRKY40 , which can bind to a W-box sequence in the promoter of the AtRab18 gene and repress its expression (Shang et al 2010).…”

Two reproductive traits show contrasting genetic architectures in Plantago lanceolata

“…Multiple genes in a complex network help regulate flowering time in response to photoperiod and temperature inArabidopsis thaliana (e.g.,Johansson & Staiger, 2014;Méndez-Vigo et al, 2016;Song et al, 2017;Song, Ito, & Imaizumi, 2013), and a similarly complex network appears to underlie latitudinal variation in flowering time in this species. This further suggests that additional undetected QTLs and/or epistatic interactions must explain the late flowering of the Swedish parent under warm conditions.…”

“…Parental effects are unlikely to explain late flowering because all parents were themselves the offspring of parents that had been raised and that had reproduced in similar environmental conditions(Lacey et al, 2010). Multiple genes in a complex network help regulate flowering time in response to photoperiod and temperature in Arabidopsis thaliana (e.g.,Johansson & Staiger, 2014;Méndez-Vigo et al, 2016;Song et al, 2017;Song, Ito, & Imaizumi, 2013), and a similarly complex network appears to underlie latitudinal variation in flowering time in this species.…”

“…Two molecular pathways that independently could thermoregulate anthocyanin accumulation have recently been identified in A. thaliana and in apple. Phytochrome B (PHYB), an important regulator of light-and temperature-mediated flowering time(Gu et al, 2019;Legris, Nieto, Sellaro, Prat, & Casal, 2017;Song et al, 2017) helps to regulate flowering via its effect on the COP1 (constitutive photomorphogenic 1) ligase. However, an indirect effect of this is that PHYB may also contribute to anthocyanin accumulation in leaves(Wu et al, 2018).…”