Breeding with dominant genic male-sterility genes to boost crop grain yield in the post-heterosis utilization era

The global population is predicted to grow by 25% and reach 10 billion the mid-21st century (Hickey et al., 2019Hickey L.T. A N.H. Robinson H. Jackson S.A. Leal-Bertioli S.C.M. Tester M. Gao C. Godwin I.D. Hayes B.J. Wulff B.B.H. Breeding crops feed billion.Nat. Biotechnol. 2019; 37: 744-754Crossref PubMed Scopus (216) Google Scholar). To meet food demands of growing with limited agricultural land fresh water resources, greater more consistent crop production under fluctuating climate conditions, including various environmental stresses, must be achieved reducing resource inputs minimizing impacts (Bailey-Serres 2019Bailey-Serres J. Parker J.E. Ainsworth E.A. Oldroyd G.E.D. Schroeder J.I. Genetic strategies for improving yields.Nature. 575: 109-118Crossref (236) Thanks extensive use semi-dwarf Green Revolution varieties single-cross hybrids major (e.g., rice maize), grain yield has increased steeply over past 60 years (Figure 1A 1B ). For example, widespread cultivation led first increase in China from 1961 1976. Subsequently, discovery cytoplasmic male sterility photo-thermal sensitive lines enabled development utilization hybrid significantly 1977 2000 1C). Similarly, maize production, manual or mechanical detasseling a feasible relatively efficient method breeding producing varieties, greatly due heterosis double- triple-cross 1941 1960 1996 However, since approximately 2000, pace slowed cannot demand ever-growing human post-heterosis era. Meeting challenge increasing will require integration heterosis, multiple desirable traits/genes, advanced technologies genetic modification [GM]). Nearly half all crops, maize, sorghum, sugar cane, rapeseed, are cross-pollinated 1D), making boost both vital. Maize provides one example: this monoecious plant bears separate (tassel) female (ear) flowers on same plant, tassel growth competes ear assimilates nutrients during early stages reproductive development, especially when resources restricted stressful conditions. This competition can lead defective decreased (Xu 2012Xu G. Fan X. Miller A.J. Plant nitrogen assimilation efficiency.Annu. Rev. Biol. 2012; 63: 153-182Crossref (964) Scholar; Fox 2017Fox T. DeBruin Haug Collet K. Trimnell Clapp Leonard A. Li B. Scolaro E. Collinson S. Glassman al.A single point mutation Ms44 results dominant improves efficiency maize.Plant 2017; 15: 942-952Crossref (49) Loussaert 2017Loussaert D. Pablo San Martin Schussler Pape R. Mongar N. Albertsen al.Genetic (Ms44) increases yield.Crop Sci. 57: 2718-2728Crossref (12) Wan 2020Wan Wu Z. An Tian Y. Lipid metabolism: critical roles fertility other aspects plants.Mol. Plant. 2020; 13: 955-983Abstract Full Text PDF (31) Zhu 2020Zhu Long Xue Xie Ma Zhang Guan Niu al.Normal structure function endothecium chloroplasts maintained ZmMs33-mediated lipid biosynthesis tapetal cells anther maize.Mol. 1624-1643Abstract (13) Many studies have reported that reduction apical dominance through improve kernel number conditions such as shade, low nitrogen, drought stress (Weingartner 2002Weingartner U. Kaeser O. Stamp P. Combining xenia 2002; 42: 1848-1856Crossref (38) 2020Gao Sun L. Ren J.-H. Liang X.-G. Shen Lin Zhao Chen X.-M. Zhou S.-L. Detasseling shade stress.Agric. For. Meteorol. 280https://doi.org/10.1016/j.agrformet.2019.107811Crossref (7) lack methods utilizing genic male-sterility traditional breeding, ability not yet widely applied. With advances modern technology, several biotechnology-based systems been developed rice, wheat (Wan 2019Wan Dong genes their applications breeding: progress perspectives.Mol. 12: 321-342Abstract (52) Scholar), thereby enabling applicable (DGMS) (Fox 2020An Duan Liu Yuan Hou Q. al.Molecular regulation ZmMs7 required system species.Proc. Natl. Acad. U S 117: 23499-23509Crossref (16) Thus, DGMS may used parents seed many crops. value parent like recessive (RGMS) replace emasculation (Wu 2016Wu T.W. M.R. Wang Xu R.J. Cigan A.M. Huffman G.A. Garnaat C.W. Hershey M.C. Development novel cross-pollinating crops.Plant 2016; 14: 1046-1054Crossref (88) 2019An al.ZmMs30 encoding GDSL lipase essential valuable 343-359Abstract (48) Qi 2020Qi Huang Genome editing enables next-generation technology.Mol. 1262-1269Abstract (15) Furthermore, highly sustainable commodity using 50:50 mixture male-sterile male-fertile F1 seeds, promoting energy assimilate partitioning into organs plants, Munsch 2010Munsch M.A. Christov N.K. Foueillassar X.M. Hüsken Camp K.-H. Weider Grain pollen containment plus-hybrids could acceptance transgenic maize.Crop 2010; 50: 909-919Crossref Scholar) compared 100% plants rely heavily fertilization Originally, was problematic because efficiently self-pollinated seed-sorted. Recently, at least two technical tested Scholar natural mutant strategy similar control (Zhang 2018Zhang Fang W. al.Construction multicontrol line based gene PHD-finger transcription factor.Plant 2018; 16: 459-471Crossref (63) generate maintainer line. In strategy, propagated self-pollination followed selection red fluorescent whereas homozygous non-transgenic (Ms44/Ms44) produced sibling maintainer. When crossed fertile inbred line, completely seeds (Ms44/+) then planted together near-isogenic adequate allo-pollination. Notably, derived up 8.5% tassel–ear Nevertheless, it difficult develop new elite marker-assisted backcrossing locus construct selected simultaneously. Most recently, simpler but broadly Arabidopsis premature expression driven p5126 promoter coupled fluorescence seed-sorting module (i.e., p5126-ZmMs7M construct) (An show stable complete without any grains, vegetative organ normal. produces normally colored nearly 1:1 ratio after pollination its sibling. Given always exists heterozygote cross between include 50% seeds. types simultaneously field, ears pollinated 1E). does waste (anther pollen) instead apportions them fully growth, environments. Compared systems, technology (like system) advantages. First, combining potential benefits allo-pollination (the Xenia effect) Second, contain which directly field sorting separation processes (Loussaert Third, eliminate release environment, safer ecosystem, planting GM traits background (Munsch Finally, recurrent pyramid high and/or salinity tolerance) Xia 2017Xia Zou Gu TRIM insertion Ms2 causes wheat.Nat. Commun. 8: 15407Crossref (46) transgene elements, regulated policies some countries. It also integrate post-Green create technologies. nutrient efficiency, tolerance resilience abiotic biotic ideal architecture, enhanced photosynthesis carbon fixation, filling rate pyramided introduced integrating high-throughput phenotyping genotyping, double haploid utilization, speed genome editing, genomic 1C integrated (including DGMS) an way while damage, keeping challenges changing environment ever-increasing population. summary, combined next green revolution only Widespread adoption enable models 1E), ultimately helping ensure security agriculture. research supported National Key Research Program ( 2018YFD0100806 , 2018YFD1000702 2017YFD0102001 2017YFD0101201 ), Natural Science Foundation 31771875 31871702 31971958 Fundamental Funds Central Universities 06500136 No conflict interest declared.