Uncovering the transcriptional response of popcorn (Zea mays L. var. everta) under long-term aluminum toxicity

Abstract

To date, the investigation of genes involved in Al resistance has focused mainly on microarrays and short periods of Al exposure. We investigated genes involved in the global response under Al stress by tracking the expression profile of two inbred popcorn lines with different Al sensitivity during 72 h of Al stress. A total of 1003 differentially expressed genes were identified in the Al-sensitive line, and 1751 were identified in the Al-resistant line, of which 273 were shared in both lines. Genes in the category of “response to abiotic stress” were present in both lines, but there was a higher number in the Al-resistant line. Transcription factors, genes involved in fatty acid biosynthesis, and genes involved in cell wall modifications were also detected. In the Al-resistant line, GST6 was identified as one of the key hub genes by co-expression network analysis, and ABC6 may play a role in the downstream regulation of CASP-like 5. In addition, we suggest a class of SWEET transporters that might be involved in the regulation of vacuolar sugar storage and may serve as mechanisms for Al resistance. The results and conclusions expand our understanding of the complex mechanisms involved in Al toxicity and provide a platform for future functional analyses and genomic studies of Al stress in popcorn.

Brown midrib mutant and genome‐wide association analysis uncover lignin genes for disease resistance in maize

“…A number of nonlignin‐related candidate genes for resistance to NLB were identified via GWAS that can also be harnessed in breeding for resistance to NLB in silage or nonsilage maize. Associations for resistance to NLB in genes previously identified in maize for diverse functions, such as resistance to Aspergillus flavus (pco102102; Liu et al., 2021), fall armyworm ( er2 ; Kamweru et al., 2022), drought ( nfy2 ; Nelson et al., 2007), heat ( hsp5 ; Qian et al., 2019; Jiang et al., 2021), waterlogging ( prolyl 4‐hydroxylase 9, proh9 ; Zou et al., 2011), aluminum toxicity ( almt16; Krill et al., 2010; Pinto et al., 2021), and days to anthesis (IDP22; Bu et al., 2021), indicate putative pleiotropic sources of resistance that spans biotic and abiotic stress tolerances.…”