A Novel Senescence-Specific Gene (ZmSAG39) Negatively Regulates Darkness and Drought Responses in Maize

Abstract

The papain-like cysteine proteases (PLCPs) is a subfamily of cysteine proteases that plays an important role in leaf senescence, and some of its members are involved in the regulation of plant growth and development under stress. In this study, we cloned a new gene, ZmSAG39, from maize. Expression profile analysis showed that ZmSAG39 was induced by darkness and drought treatments. In addition, the ZmSAG39 overexpression in maize accelerated the senescence of maize leaves under darkness and drought treatments. However, the knockout of ZmSAG39 in maize enhanced the resistance of maize to darkness and drought stresses and reduced the degree of senescence of maize leaves. Under drought stress, compared with WT plants, the knockout lines had a higher seed germination rate, seedling survival rate and chlorophyll content, and lower reactive oxygen species (ROS) level and malondialdehyde (MDA) content. In addition, quantitative real-time PCR (qRT-PCR) analysis showed that ZmSAG39 negatively regulated some stress-related genes but positively regulated senescence-related genes under darkness and drought stress conditions. To summarize, these results indicate that ZmSAG39 is a senescence-related gene and plays a negative role in response to darkness and drought stresses. This study laid a theoretical foundation for the innovation of maize germplasm resources with high quality, high yield and strong stress resistance.

A Cinnamate 4-HYDROXYLASE1 from Safflower Promotes Flavonoids Accumulation and Stimulates Antioxidant Defense System in Arabidopsis

“…The transformed cultures were cultured separately in SD/-Leu-Trp medium and incubated at 30 °C for 3–5 days before transferring the yeast colonies to a SD/-Ade-His-Leu-Trp medium. The growth of each strain was observed after 3–5 d. LacZ reporter genes were additionally detected using the X-α-gal-containing color development solution [ 50 ]. Similarly, pxy106-CtC4H1 and pxy104-CtPAL1 recombinant plasmids were transferred to the EHA105 Agrobacterium receptor cells, and single colonies were subjected to growth on the YEP solid medium containing Spec+ antibiotic.…”

The roles of plant proteases and protease inhibitors in drought response: a review

“…A summary of these studies is also given in Table 6. For example, Wang et al (2022) investigated the role of the maize (Z. mays) senescence-associated gene, ZmSAG39 encoding a cysteine protease in maize plants subjected to either darkness or drought stress. The genotypes used were wildtype, transgenic ZmSAG39 overexpression (OE) lines and ZmSAG39 knockout lines.…”

“…Regulation and functions of plant proteases and protease inhibitors extrapolated from various drought-stress studies. et al, 2001;Hieng et al, 2004;Huang et al, 2007;Chen et al, 2010;Simova-Stoilova et al, 2010;Ford et al, 2011;Yao et al, 2012;Ashoub et al, 2013;Jedmowski et al, 2014;Faghani et al, 2015;Tiwari et al, 2015;Wang et al, 2015;Cheng et al, 2016;Chmielewska et al, 2016;Wu et al, 2016;Islam et al, 2017;Tan et al, 2017;Gomez-sanchez et al, 2019;Goche et al, 2020;Malefo et al, 2020;Sebastiań et al, 2020;Mishra et al, 2021;Wang et al, 2022). Moloi and Ngara 10.3389/fpls.2023.1165845 Frontiers in Plant Science frontiersin.org genes.…”

“…Plant gene function can also be studied using knockout or knockdown mutants with total or partial loss of gene function ( Bolle et al., 2011 ). Several studies have utilized such mutants of proteases or protease inhibitors to study their role during plant growth and drought response ( Islam et al., 2017 ; Gomez-sanchez et al., 2019 ; Mishra et al., 2021 ; Wang et al., 2022 ). A summary of these studies is also given in Table 6 .…”

“…The authors concluded that ZmSAG39 is associated with leaf senescence, and its increased expression under darkness and drought enhances the sensitivity of maize plants to stress. As such, the knocking out of ZmSAG3 from maize enhanced the resistance of maize plants to darkness and drought tolerance and delayed leaf senescence ( Wang et al., 2022 ).…”