The Core Subunit of A Chromatin-Remodeling Complex, ZmCHB101, Plays Essential Roles in Maize Growth and Development

Abstract

ATP-dependent chromatin remodeling complexes play essential roles in the regulation of diverse biological processes by formulating a DNA template that is accessible to the general transcription apparatus. Although the function of chromatin remodelers in plant development has been studied in A. thaliana, how it affects growth and development of major crops (e.g., maize) remains uninvestigated. Combining genetic, genomic and bioinformatic analyses, we show here that the maize core subunit of chromatin remodeling complex, ZmCHB101, plays essential roles in growth and development of maize at both vegetative and reproductive stages. Independent ZmCHB101 RNA interference plant lines displayed abaxially curling leaf phenotype due to increase of bulliform cell numbers, and showed impaired development of tassel and cob. RNA-seq-based transcriptome profiling revealed that ZmCHB101 dictated transcriptional reprogramming of a significant set of genes involved in plant development, photosynthesis, metabolic regulation, stress response and gene expressional regulation. Intriguingly, we found that ZmCHB101 was required for maintaining normal nucleosome density and 45 S rDNA compaction. Our findings suggest that the SWI3 protein, ZmCHB101, plays pivotal roles in maize normal growth and development via regulation of chromatin structure.

Maize Dek15 Encodes the Cohesin-Loading Complex Subunit SCC4 and Is Essential for Chromosome Segregation and Kernel Development

“…The chromatin remodeling complexes play a vital role in regulating chromatin structure and assembly, the dynamic nature of chromatin, DNA methylation, and histone modification (Ho and Crabtree, 2010). In maize, CHB101 is involved in maintaining nucleosome density and chromosome structure (Yu et al, 2016). In Arabidopsis, the SWI3 proteins may alter the interaction between the histones and DNA to affect plant development and transcription (Sarnowski et al, 2005;Zhu et al, 2013).…”

Chromatin Remodeling Protein ZmCHB101 Regulates Nitrate-Responsive Gene Expression in Maize

“…Previously, we reported that ZmCHB101 may regulate the expression of genes involved in nitrogen compound metabolic process (Yu et al, 2016). To investigate this possibility, the seeds of WT plants and ZmCHB101-RNAi lines were incubated on moist filter paper at 28°C for 3 days to allow germination.…”

“…ZmCHB101-RNAi lines, RS1 and R101, have been described previously (Yu et al, 2016), in which ZmCHB101 transcript levels were approximately 7% and 16% of that in the WT, respectively. Seeds of the WT and ZmCHB101-RNAi lines were sterilized using 1% sodium hypochlorite and incubated on moist filter paper at 28°C for 3 days for germination.…”

“…Based on the type of SNF2 family ATPase subunits, the ATP-dependent CRCs are divided into four subfamilies: SWI2/SNF2, IMITATION SWITCH (ISWI), Mi-2/ Chromodomain-Helicase-DNA (CHD)-binding protein (Mi-2/ CHD), and INO80 (Sarnowska et al, 2016). Previous studies revealed that SWI3 proteins, the core components of the SWI/ SNF CRCs, play essential roles in plant growth and development (Sarnowski et al, 2005;Yu et al, 2016). The AtSWI3 genes regulate root elongation and leaf and reproductive organ development (Sarnowski et al, 2005).…”

“…Furthermore, mutations in AtSWI3D lead to severe dwarfism and alterations in the number and development of flower organs (Zhou et al, 2003;Sarnowski et al, 2005). The maize SWI3 protein, ZmCHB101, plays an essential role in leaf development and dehydration and abscisic acid responses (Yu et al, 2016;Yu et al, 2018;Yu et al, 2019); however, it is unknown whether SWI/SNF complexes participate in nitrate responses.…”