Table 2.
Selected cell-wall-modification-related gene candidates for enhancing drought tolerance in plants.
| Host species | Gene name | Function | Strategy | Observed phenotype/outcome | References |
|---|---|---|---|---|---|
| Malus domestica | MdMRLK2 | A FERONIA receptor kinase involved in plant growth, development and stress response | Overexpression | Enhanced energy levels, free amino acids, ABA content, and drought tolerance in overexpressing transgenic apple plants. | (Jing et al., 2023) |
| Arabidopsis thaliana (Arabidopsis) | THESEUS1 (THE1) | A CrRLK1L RPK cell wall integrity sensor, required for hypocotyl cell elongation, responses to cell wall damage induced by cellulose biosynthesis inhibition and by pathogen infection. | Mutations and GFP fusion OE analyses experiments. | Mutations in THE1 and overexpression of THEI respectively attenuated and enhanced growth inhibition and ectopic lignification in seedlings mutated in cellulose synthase CESA6 without influencing the cellulose deficiency. | (Hématy et al., 2007) |
| Arabidopsis | THE1 | A CrRLK1L RPK cell wall integrity sensor, required for hypocotyl cell elongation, responses to cell wall damage induced by cellulose biosynthesis inhibition and by pathogen infection (Hématy et al., 2007; Engelsdorf et al., 2018) | Seedlings treated with cellulose biosynthesis inhibitor isoxaben (ISX), and turgor pressure influencer sorbitol, and effects visualized using Brillouin microscopy. | THEI modulated changes in turgor pressure and cell wall stiffness in Arabidopsis roots via ABA biosynthesis. | (Bacete et al., 2022) |
| Arabidopsis | RPK1 | A PM-localized receptor-like protein kinase that functions as a regulator of ABA signaling in Arabidopsis. | Gene characterization, expression analyses, and several abiotic stress treatments analyses. | RPK1 was rapidly induced by ABA, dehydration, salt and cold treatments, suggesting its role in abiotic stress response. | (Hong et al., 1997) |
| Arabidopsis | RPK1 | A PM-localized receptor-like protein kinase that functions as a regulator of ABA signaling in Arabidopsis. | Disruption and overexpression experiments. | Transgenics overexpressing RPK1 protein showed increased ABA sensitivity in their root growth, stomatal closure, less transpirational water loss, and enhanced drought tolerance. OE plants also showed enhanced oxidative stress tolerance. | (Osakabe et al., 2010) |
| Arabidopsis |
AtCesA8/IRX1
(lew2-1 and lew2-2 ) |
Involved in cellulose synthesis | Mutations/disruption | Mutants were more tolerant to drought and osmotic stresses. Higher accumulation of ABA and osmolites in lew2 mutants than Wt. Higher expression of stress-inducible marker gene RD29A, proline synthesis-related gene P5CS, and an ABA synthesis-related gene SDR1 in lew2 than in Wt. | (Chen et al., 2005) |
| Tobacco (Nicotiana tabacum) | TaEXPB23 | Wheat β-expansin gene | Overexpression under the control of a 35S promoter | TaEXPB23-OE tobacco showed slower water loss rate, and their cells maintained their structural integrity better than Wt under drought. Further, OE lines had higher photosynthetic performance and lower electrolyte leakage than Wt. | (Li et al., 2011) |
| Tobacco | TaEXPB23 | Wheat β-expansin gene | Overexpression under the root-specific promoter PYK10. | P10::TaEXPB23 plants showed an increase in lateral roots, improved water status, higher photosynthetic performance, reduced ROS, and enhanced drought tolerance than 35S::TaEXPB23 and WT plants. | (Li et al., 2015) |
| Tobacco | TaEXPB23 | Wheat β-expansin gene | Overexpression | Increased the activity of CW-bound PRX and enhanced oxidative stress tolerance in transgenic tobacco. | (Han et al., 2015) |
| Rice (Oryza sativa) | OsEXPA8 | Root-specific gene involved in cell extension | Overexpression | Enhanced rice growth and root system architecture | (Ma et al., 2013) |
| Tobacco | TaEXPA2 | Involved in cell wall expansion control | Constitutive expression | Enhanced osmotic adjustment, antioxidant capacity, seed production, and drought tolerance in transgenic plants. | (Chen et al., 2016) |
| Arabidopsis | AnEXPA1 and AnEXPA2 | Regulation of cell wall loosening | Overexpression | Enhanced drought tolerance and survival rate in OE transgenic plants, | (Liu et al., 2019) |
| Soybean (Glycine max) | GmEXPB2 | β-expansin gene | Overexpression and mutant analyses | GmEXPB2 expression was induced by mild water deficiency and enhanced root drought tolerance in overexpressing plants. | (Guo et al., 2011) |
| Roses (Rosa hybrida) and Arabidopsis | RhNAC 2 and RhEXPA4 | Involved in dehydration tolerance regulation during rose petal extension | Silencing of NAC2 and EXPA4; Overexpression of EXPA4 | Silencing of the two genes reduced the recovery of intact petals or petal discs during rehydration; Overexpression of RhNAC2 and RhEXPA4 conferred strong drought tolerance in transgenic Arabidopsis, and 20 CW-related genes were up-regulated in RhNAC2-OE Arabidopsis. | (Dai et al., 2012) |
| Maize | Cinnamoyl-CoA reductase 1, and 2 | Involved in lignin biosynthesis | Up-regulated expression | Increased root lignification | (Fan et al., 2006) |
| Cluster bean | PAL1, C4H, 4CL, CCR, CCOMT, and CAD6 | Involved in lignin biosynthesis | Up-regulated expression | Increased lignin synthesis, water-flow resistance, sustained nutrient transport, and enhanced drought tolerance. | (Narayan et al., 2023) |
| Rice | CLD1/SRL1 | Encodes a glycophosphatidylinositol (GPI)-anchored membrane protein that modulates leaf rolling and other aspects of growth and development. Facilitates plasma membrane – cell wall communication. | Mutation analysis | cld1 mutant showed significant decreases in cellulose and lignin contents in leaf secondary CWs; loss of function of CLD1/SRL1 affected CW formation. Additionally, cdl1 exhibited decreased water-retaining capacity, more rapid leaf water loss, lower leaf RWC, and reduced drought tolerance. | (Li et al., 2017) |
| Arabidopsis | IRX14/IRX14-LIKE | Glycosyl transferases mediating glucuronoxylan biosynthesis | Mutation analyses | Improved glucuronoxylan biosynthesis and drought tolerance in Arabidopsis. | (Keppler and Showalter, 2010) |
| Tobacco | CrPOD1 | Involved in cell wall metabolism, stress response, etc. | Overexpression | Enhanced seed germination, and salinity and drought stress tolerances. | (Kumar et al., 2012). |
| Arabidopsis | FERONIA (FER) | Cell wall integrity maintenance | Mutants analysis | Maintained cell-wall integrity in FER-harbouring plants, whereas fer and mur1 mutants showed increased root cell-wall softening and disrupted pectin cross-linking under salinity. Treatment with Ca2+ and borate rescued cell-wall integrity defects, and facilitated pectin cross-linking and Ca2+ signaling in fer mutants. | (Feng et al., 2018) |
| Arabidopsis | HAESA-LIKE3 (HSL3) | A leucine-rich repeat (LRR) RLK protein | Overexpression and mutant analysis experiments. | HSL3 negatively regulated stomatal closure and drought stress response by modulating the level of H2O2 in the guard cells. | (Liu et al., 2020) |
| Arabidopsis | RLP44 | A receptor-like protein which mediates the activation of BR signaling via direct interaction with a BR coreceptor BAK1. | Mutations and GFP fusion OE analyses, coupled with confocal laser-scanning analysis. | RLP44 activated the BR signaling module in response to PMEI overexpression-induced cell wall (pectin) perturbation. | (Wolf et al., 2014) |
| Arabidopsis | AtWAKL10 | Wall-associated kinases | Knockdown mutation | The atwakl10 knockout mutant showed enhanced tolerance to drought but reduced tolerance to salinity. | (Bot et al., 2019) |
| Arabidopsis | AtRPS2 | Nucleotide-binding and leucine-rich repeat kinase | Constitutive expression | AtRPS2-OE transgenic plants showed higher survival rates and improved drought and salinity stress tolerance than Wt. | (Wu et al., 2023) |
| Wheat (Triticum aestivum) | TaPOD04 | Cell wall extension, at the root apex | RT-qPCR | Sustained root growth and RWC of root tissues, and increased transcript abundance of TaPOD04 in root apex in response to PEG-induced osmotic stress. | (Csiszár et al., 2012) |
| Safflower and Arabidopsis | CtCYP71A1 | Cytochrome P450 family gene involved in biosynthesis and catabolism of secondary metabolites | Overexpression | Increased root lignin accumulation, enhanced regulation of several lignin-biosynthesis-related genes, and drought tolerance in OE safflower and Arabidopsis lines than Wt and antisense plants. | (Zhang Q. et al., 2023). |
| Rice | OsNAC17 | Rice TF | Overexpression | Positively influenced several lignin biosynthesis-related genes, enhanced leaf and root lignification, and improved drought tolerance in transgenic rice. | (Jung et al., 2022) |
| Paeonia ostia | PoWRKY17 | Transcriptional regulation of lignin and other secondary metabolism-related genes | Overexpression | Enhanced lignin accumulation, activated expression PoCCoAOMT genes, and drought tolerance. | (Luan et al., 2023) |
| Rice | SiMYB56 | Transcriptional regulation of lignin biosynthesis related genes | Overexpression | Enhanced lignin content, ABA synthesis, expression of lignin and ABA synthesis-related genes, and drought tolerance in transgenic rice plants. | (Xu et al., 2020) |
| Rice | OsTF1L | A homeodomain leucine zipper TF involved in regulation of lignin biosynthesis | Overexpression | Elevated shoot lignin accumulation, stomatal closure, and enhanced drought tolerance in transgenic rice. | (Bang et al., 2019) |
| Rice | OsERF71 | A drought-responsive AP2/ERF TF involved in regulation of lignin biosynthesis | Root-specific overexpression | Orchestrated root architecture adjustment, enhanced the expression of CW loosening and lignin biosynthetic genes, eg. OsCCR1. | (Lee et al., 2016) |
| Rice | OsNAC10 | Rice TF | Overexpression under the control of constitutive promoter GOS2 and root-specific promoter RCc3 | Root-specific overexpression enlarged roots, and enhanced rice drought tolerance and grain yield under field drought conditions. | (Jeong et al., 2010) |
| Rice | OsNAC9 | Rice TF | Overexpression | Promoted root architecture adjustment and improved drought tolerance and grain yield in rice under field drought conditions. | (Redillas et al., 2012) |
| Rice | OsNAC5 | Rice TF | Overexpression | OsNAC5 activated OsCCR10, modulated lignin accumulation, minimized water loss rate, enhanced photosynthetic performance and vegetative stage drought tolerance in overexpressing rice plants. | (Bang et al., 2022) |
| Arabidopsis | AtMYB41 | Encodes an R2R3-MYB TF involved in regulating cell expansion and cuticle deposition in response to abiotic stress | Overexpression | Transgenic OE lines showed a pleiotropic phenotype similar to that shown by mutants that affect cuticle biosynthesis, viz., enhanced sensitivity to desiccation and enhanced permeability of leaf surfaces. Expression of cuticle metabolism-, CW modification-, cell expansion-, and lipid metabolism-related genes was differentially modulated. | (Cominelli et al., 2008) |
| Arabidopsis | PtoPME35 | Modulates stomatal function | Overexpression | Enhanced stomatal functioning and drought tolerance in transgenic Arabidopsis. | (Yang W. et al., 2020) |
| Arabidopsis | CaPMEI1 | Pectin methyltransferase | Overexpression | Transgenic plants overexpressing CaPMEI1 exhibited improved drought tolerance, through increased germination rate and seedling growth than Wt. | (An et al., 2008; Wormit and Usadel, 2018) |
| Arabidopsis | CaXTH3 | Encodes an XTH homolog | Constitutive expression | Enhanced drought and salinity tolerance in transgenic Arabidopsis. | (Cho et al., 2006) |
lew-2-1, and 2-2, leaf wilting 2-1 and leaf wilting 2-2; AnEXPA1 and AnEXPA2, Ammopiptanthus nanus expansins 1 and 2, respectively; AtWAKL10, Arabidopsis thaliana wall-associated kinase Like10; CaXTH3, Capsicum annuum xyloglucan endotransglucosylase/hydrolase 3; CLD1/SRL1, CURLED LEAF AND DWARF 1/SEMI-ROLLED; CrPOD1, Catharanthus roseus peroxidase 1; IRX14 and IRX14L, closely related glycosyl transferases in the glycosyl transferase 43 (GT43) family of Arabidopsis; RPK1, receptor-like protein kinase 1; RLP44, receptor –like protein 44; leaf RWC, leaf relative water content; OE, overexpressing; OsCCR1, OsCINNAMOYL-COENZYME A REDUCTASE 1; OsTF1L, Oryza sativa transcription factor 1-like; OsERF71, Oryza sativa drought-responsive AP2/ERF transcription factor; PtoPME35, Populus tomentosa PME35; P5CS, pyrroline-5-carboxylate synthase; SDR1, alcohol dehydrogenase/reductase; SiMYB56, Setaria italic MYB56; RT-qPCR, real-time quantitative PCR. Table modified from (Houston et al., 2016; Wang et al., 2016).