Hormone and RNA-seq analyses reveal the mechanisms underlying differences in seed vigour at different maize ear positions
ABA/GA4 ratio, stress resistance, carbon and nitrogen metabolism, and chromatin structure play important roles in vigour differences of seeds located at different maize ear positions.
Seed vigour, which ensures rapid and uniform field emergence across diverse environments, differs at different maize ear positions. However, little is known regarding the associated mechanisms. In this study, we determined that seed vigour, stress resistance, and carbon and nitrogen metabolism were higher in seeds from middle and bottom section of the ear, while the ABA/GA4 ratio in the embryos was significantly lower. Compared with the seeds subjected to repeated pollination during silking, less variation in seed vigour and the ABA/GA4 ratio in the embryos was observed in seeds at different ear positions subjected to single pollination after complete silking. This indicated that single pollination can reduce, but not eliminate, the differences in seed vigour at different ear positions. RNA-seq analysis indicated that the seed vigour differences at the different locations of the maize ears of the single pollinated treatment were related to carbon and nitrogen metabolism. In contrast, the differences in seed vigour under repeated pollination were related to chromatin structure. The present study contributes to our understanding of the mechanisms underlying differences in seed vigour at different positions on the maize ear.
KeywordsABA GA4 Seed position Seed vigour Zea mays
We thank Professor Gerhard Leubner-Metzger and Waheed Arshad, Royal Holloway, University of London, United Kingdom, for reading and providing valuable comments on this manuscript. This work was supported by the grants from the National Natural Science Foundation of China (Grant Nos. 31271808 and 31771890).
YL and CZ planned and designed the research. MW, HQ, HZ and SL conducted experiments. WM, YL and CZ analyzed the data. WM and YL wrote the paper.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
- Deng ZJ, Hu XF, Ai XR, Yao L, Deng SM, Pu X, Song SQ (2015) Dormancy release of Cotinus coggygria seeds under a pre-cold moist stratification: an endogenous abscisic acid/gibberellic acid and comparative proteomic analysis. N For 47:105–118Google Scholar
- Henikoff S, Smith MM (2015) Histone variants and epigenetics. CSH Perspect Biol 7:a019364Google Scholar
- Marquez-Millano A, Elam WW, Blanche CA (1991) Influence of accelerated aging on fatty acid composition of slash pine (Pinus Elliottii engelm. var. Elliottii) seeds. J Seed Technol 15:29–41Google Scholar
- Okamoto M, Tatematsu K, Matsui A, Morosawa T, Ishida J, Tanaka M, Endo TA, Mochizuki Y, Toyoda T, Kamiya Y, Shinozaki K, Nambara E, Seki M (2010) Genome-wide analysis of endogenous abscisic acid-mediated transcription in dry and imbibed seeds of Arabidopsis using tiling arrays. Plant J 62:39–51CrossRefGoogle Scholar
- Petla BP, Kamble NU, Kumar M, Verma P, Ghosh S, Singh A, Rao V, Salvi P, Kaur H, Saxena SC, Majee M (2016) Rice PROTEIN l-ISOASPARTYL METHYLTRANSFERASE isoforms differentially accumulate during seed maturation to restrict deleterious isoAsp and reactive oxygen species accumulation and are implicated in seed vigor and longevity. New Phytol 211:627–645CrossRefGoogle Scholar
- Rajeswari MR, Jain A (2002) High-mobility-group chromosomal proteins, HMGA1 as potential tumour markers. Curr Sci India 82:838–844Google Scholar