Overexpression of ZmIPT2 gene delays leaf senescence and improves grain yield in maize

Abstract

Cytokinins (CTKs) are a major phytohormone group that are significant in the promotion of cellular division, growth, and divergence. Isopentenyl transferase (IPT) regulates a rate-limiting step in plant CTK synthesis, promotes the synthesis of isopentenyl adenonucleotides from 5-AMP and isopentenyl pyrophosphate, and then converts both these chemicals into various CTKs. Here, the full-length cDNA of ZmIPT2, which encodes 322 amino acids, was isolated and was introduced into a maize inbred line by Agrobacterium-mediated transformation. In both controlled environments and field experiments, the overexpression of ZmIPT2 gene in the transformed plants delayed leaf senescence. Compared to the receptor line, the transgenic maize lines retained higher chlorophyll levels, photosynthetic rates, and cytokinin content for an extended period of time, and produced significantly higher grain yield by a margin of 17.71–20.29% under normal field planting conditions. Subsequently, ten possible genes that interacted with ZmIPT2 were analyzed by qRT-PCR, showing that the expression pattern of GRMZM2G022904 was consistent with ZmIPT2 expression. Through comprehensive analysis, we screened for transgenic lines with stable inheritance of ZmIPT2 gene, clear functional efficiency, and significant yield improvement, in order to provide theoretical basis and material support for the breeding of new high-yield transgenic maize varieties.

Genome-wide identification of GA2ox genes family and analysis of PbrGA2ox1-mediated enhanced chlorophyll accumulation by promoting chloroplast development in pear

“…Phytohormones are small molecules that modulate diverse physiological and cellular responses and play crucial roles in mediating Chl accumulation [ 70 , 71 ]. Extensive investigations have revealed the positive roles of IAA, CTK, GA, and SA [ 72 – 75 ], and the negative roles of ETH, JA, and ABA in Chl accumulation [ 76 – 78 ]. However, Previous studies reported a marked decline in the Chl content in oil palm [ 79 ] and Arabidopsis [ 80 ] following GA 3 and IAA treatments, respectively.…”

Integration of GWAS, linkage analysis and transcriptome analysis to reveal the genetic basis of flowering time-related traits in maize

“…Zm00001d011673, which is also named fps2 , encodes the farnesyl diphosphate synthase 2 protein. A previous study showed that Zm00001d011673 can interact with ZmIPT2, which can regulate leaf senescence and grain yield in maize ( Song et al., 2022 ).…”

Genome-Wide Association Study Identified Novel SNPs Associated with Chlorophyll Content in Maize

“…Chlorophyll content is an indicator of photosynthesis activity, which can directly affect photosynthetic efficiency [44][45][46]. A large number of functional genes related to chlorophyll have been identified by analysis of many mutants in maize, rice, and other species [47][48][49]. However, chlorophyll content is a quantitative trait controlled by multiple genes, which requires further study on its function.…”