Protein Profiles Reveal Diverse Responsive Signaling Pathways in Kernels of Two Maize Inbred Lines with Contrasting Drought Sensitivity

Abstract

Drought stress is a major factor that contributes to disease susceptibility and yield loss in agricultural crops. To identify drought responsive proteins and explore metabolic pathways involved in maize tolerance to drought stress, two maize lines (B73 and Lo964) with contrasting drought sensitivity were examined. The treatments of drought and well water were applied at 14 days after pollination (DAP), and protein profiles were investigated in developing kernels (35 DAP) using iTRAQ (isobaric tags for relative and absolute quantitation). Proteomic analysis showed that 70 and 36 proteins were significantly altered in their expression under drought treatments in B73 and Lo964, respectively. The numbers and levels of differentially expressed proteins were generally higher in the sensitive genotype, B73, implying an increased sensitivity to drought given the function of the observed differentially expressed proteins, such as redox homeostasis, cell rescue/defense, hormone regulation and protein biosynthesis and degradation. Lo964 possessed a more stable status with fewer differentially expressed proteins. However, B73 seems to rapidly initiate signaling pathways in response to drought through adjusting diverse defense pathways. These changes in protein expression allow for the production of a drought stress-responsive network in maize kernels.

Quantitative Proteomic Analyses Identify ABA-Related Proteins and Signal Pathways in Maize Leaves under Drought Conditions

“…The protein-protein interaction network analysis indicated that glutathione S-transferase had interactions with six proteins, suggesting its important role in antioxidative defense. Other studies indicated that the expression levels of glutathione S-transferase and glutathione peroxidase were scarcely affected in drought-tolerant maize genotypes but were significantly increased in drought-sensitive maize genotypes under drought conditions (Benešová et al, 2012; Yang et al, 2014). Taken together, these results show that the cooperative relations among the antioxidative proteins play an important role in redox homeostasis under drought conditions.…”

“…Xylanase inhibitor proteins are believed to play a role in plant defensive reactions (Dornez et al, 2010; Vasconcelos et al, 2011). A previous study indicated that the expression levels of dehydrin and xylanase inhibitor protein 1 were barely affected in the drought-tolerant maize line Lo964 but were significantly increased in the drought-sensitive line B73 under drought conditions (Yang et al, 2014). In the maize drought-tolerant CE704 and drought-sensitive 2023 genotypes, the expression of dehydrin RAB-17 was increased under drought stress, but the increase was greater in CE704 than in the 2023 genotype.…”

“…ABA is a vital hormone and confers tolerance to abiotic stress (Sah et al, 2016). Although there are some studies concerning proteomic analysis of maize tolerance to drought stress (Benešová et al, 2012; Yang et al, 2014), there are still few studies investigating the roles of ABA in proteomic changes during maize tolerance to drought stress. In this regard, the present study focused on the roles of ABA in drought-induced proteomic changes by comparing the ABA-deficient maize mutant vp5 and its wild-type Vp5 .…”

“…In order to avoid these hazards, cells need to depend on a complex network of molecular chaperones to prevent aggregation and promote efficient folding (Hartl et al, 2011; Kim et al, 2013). Recent advances showed that drought increased the expression levels of several sHSPs in maize leaves but decreased their expression in maize kernels (Benešová et al, 2012; Yang et al, 2014). Our previous study indicated that ABA regulated the changes in phosphorylation level of several sHSPs in maize leaves under drought stress (Hu et al, 2015).…”

Functional and Integrative Analysis of the Proteomic Profile of Radish Root under Pb Exposure

“…Isobaric tags for relative and absolute quantification (iTRAQ) is a robust mass spectrometry of protein quantitative technology, which can perform relative and absolute quantification in up to eight samples in parallel (Bindschedler and Cramer, 2011; Glibert et al, 2014). Recently, iTRAQ has been widely used for large-scale quantitative plant proteomic studies in exploration of various metabolic processes at the post-transcriptional level (Kambiranda et al, 2013; Martínez-Esteso et al, 2013) in response to various stresses (Yang et al, 2014; Li et al, 2015; Fu et al, 2016). Additionally, iTRAQ-based proteomics has been proven as a powerful method for unraveling the molecular regulatory networks involved in interactions between heavy metals and plant species, and a set of HM-responsive candidate proteins have been successfully identified.…”