Recent Advances for Drought Stress Tolerance in Maize (Zea mays L.): Present Status and Future Prospects

Abstract

Drought stress has severely hampered maize production, affecting the livelihood and economics of millions of people worldwide. In the future, as a result of climate change, unpredictable weather events will become more frequent hence the implementation of adaptive strategies will be inevitable. Through utilizing different genetic and breeding approaches, efforts are in progress to develop the drought tolerance in maize. The recent approaches of genomics-assisted breeding, transcriptomics, proteomics, transgenics, and genome editing have fast-tracked enhancement for drought stress tolerance under laboratory and field conditions. Drought stress tolerance in maize could be considerably improved by combining omics technologies with novel breeding methods and high-throughput phenotyping (HTP). This review focuses on maize responses against drought, as well as novel breeding and system biology approaches applied to better understand drought tolerance mechanisms and the development of drought-tolerant maize cultivars. Researchers must disentangle the molecular and physiological bases of drought tolerance features in order to increase maize yield. Therefore, the integrated investments in field-based HTP, system biology, and sophisticated breeding methodologies are expected to help increase and stabilize maize production in the face of climate change.

Keywords: QTL mapping; drought; genome editing; high-throughput phenotyping; maize; omics.

FIGURE 1

Drought stress sensing, perception, and signaling modulate transcription factors (TFs) that enhances reactive oxygen species (ROS) scavenging, protein turnover, osmotic regulation, and photosynthesis processes. ABA, abscisic acid; AP2, APETALA; Apx, ascorbate peroxidase; CAT, catalase; CDPK1, calcium-dependent protein kinase 1; DREB, dehydration responsive element binding gene; ERF, ethylene responsive factor; GPx, glutathione peroxidase; JA, jasmonic acid; LEA, late embryogenesis abundant; MAPK, mitogen-activated protein kinase; MYB, myeloblastosis oncogene; NAC, (NAM, ATAF 1/2, and CUC2) domain proteins; PP2Cs, 2C-type protein phosphatases; ROS, reactive oxygen species; SnRK2, SNF-related protein kinase 2; SOD, superoxide dismutase; TF, transcription factor; WRKY, family denoted by protein domain composed of a conserved WRKYGQK motif and a zinc-finger domain.

FIGURE 2

System biology-based omics approaches to strategies future basic research to decipher and develop drought tolerance maize cultivars.