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Maki T, Kusaka H, Matsumoto Y, Yamazaki A, Yamaoka S, Ohno S, Doi M, Tanaka Y. The mutation of CaCKI1 causes seedless fruits in chili pepper (Capsicum annuum). TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2023; 136:85. [PMID: 36964815 DOI: 10.1007/s00122-023-04342-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 03/08/2023] [Indexed: 06/18/2023]
Abstract
The seedless mutant tn-1 in chili pepper is caused by a mutation in CaCKI1 (CA12g21620), which encodes histidine kinase involving female gametophyte development. An amino acid insertion in the receiver domain of CaCKI1 may be the mutation responsible for tn-1. Seedlessness is a desirable trait in fruit crops because the removal of seeds is a troublesome step for consumers and processing industries. However, little knowledge is available to develop seedless chili peppers. In a previous study, a chili pepper mutant tn-1, which stably produces seedless fruits, was isolated. In this study, we report characterization of tn-1 and identification of the causative gene. Although pollen germination was normal, confocal laser microscopy observations revealed deficiency in embryo sac development in tn-1. By marker analysis, the tn-1 locus was narrowed down to a 313 kb region on chromosome 12. Further analysis combined with mapping-by-sequencing identified CA12g21620, which encodes histidine kinase as a candidate gene. Phylogenetic analysis revealed CA12g21620 was the homolog of Arabidopsis CKI1 (Cytokinin Independent 1), which plays an important role in female gametophyte development, and CA12g21620 was designated as CaCKI1. Sequence analysis revealed that tn-1 has a 3-bp insertion in the 6th exon resulting in one lysine (K) residue insertion in receiver domain of CaCKI1, and the sequence nearby the insertion is widely conserved among CKI1 orthologs in various plants. This suggested that one K residue insertion may reduce the phosphorylation relay downstream of CaCKI1 and impair normal development of female gametophyte, resulting in seedless fruits production in tn-1. Furthermore, we demonstrated that virus-induced gene silencing of CaCKI1 reduced normally developed female gametophyte in chili pepper. This study describes the significant role of CaCKI1 in seed development in chili pepper and the possibility of developing seedless cultivars using its mutation.
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Affiliation(s)
- Takahiro Maki
- Graduate School of Agriculture, Kyoto University, Kitashirakawa-oiwakecho, Sakyo-Ku, Kyoto, 606-8502, Japan
| | - Hirokazu Kusaka
- Graduate School of Agriculture, Kyoto University, Kitashirakawa-oiwakecho, Sakyo-Ku, Kyoto, 606-8502, Japan
| | - Yuki Matsumoto
- Graduate School of Agriculture, Kyoto University, Kitashirakawa-oiwakecho, Sakyo-Ku, Kyoto, 606-8502, Japan
| | - Akira Yamazaki
- Graduate School of Agriculture, Kyoto University, Kitashirakawa-oiwakecho, Sakyo-Ku, Kyoto, 606-8502, Japan
- Faculty of Agriculture, Kindai University, Naka Machi, Nara, 631-8505, Japan
| | - Shohei Yamaoka
- Graduate School of Biostudies, Kyoto University, Sakyo-Ku, Kyoto, 606-8501, Japan
| | - Sho Ohno
- Graduate School of Agriculture, Kyoto University, Kitashirakawa-oiwakecho, Sakyo-Ku, Kyoto, 606-8502, Japan
| | - Motoaki Doi
- Graduate School of Agriculture, Kyoto University, Kitashirakawa-oiwakecho, Sakyo-Ku, Kyoto, 606-8502, Japan
| | - Yoshiyuki Tanaka
- Graduate School of Agriculture, Kyoto University, Kitashirakawa-oiwakecho, Sakyo-Ku, Kyoto, 606-8502, Japan.
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Knapp JL, Bartlett LJ, Osborne JL. Re-evaluating strategies for pollinator-dependent crops: How useful is parthenocarpy? J Appl Ecol 2016; 54:1171-1179. [PMID: 28781379 PMCID: PMC5516152 DOI: 10.1111/1365-2664.12813] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Accepted: 10/07/2016] [Indexed: 11/29/2022]
Abstract
Whilst most studies reviewing the reliance of global agriculture on insect pollination advocate increasing the ‘supply’ of pollinators (wild or managed) to improve crop yields, there has been little focus on altering a crop's ‘demand’ for pollinators. Parthenocarpy (fruit set in the absence of fertilization) is a trait which can increase fruit quantity and quality from pollinator‐dependent crops by removing the need for pollination. Here we present a meta‐analysis of studies examining the extent and effectiveness of parthenocarpy‐promoting techniques (genetic modification, hormone application and selective breeding) currently being used commercially, or experimentally, on pollinator‐dependent crops in different test environments (no pollination, hand pollination, open pollination). All techniques significantly increased fruit quantity and quality in 18 pollinator‐dependent crop species (not including seed and nut crops as parthenocarpy causes seedlessness). The degree to which plants experienced pollen limitation in the different test environments could not be ascertained, so the absolute effect of parthenocarpy relative to optimal pollination could not be determined. Synthesis and applications. Parthenocarpy has the potential to lower a crop's demand for pollinators, whilst extending current geographic and climatic ranges of production. Thus, growers may wish to use parthenocarpic crop plants, in combination with other environmentally considerate practices, to improve food security and their economic prospects.
Parthenocarpy has the potential to lower a crop's demand for pollinators, whilst extending current geographic and climatic ranges of production. Thus, growers may wish to use parthenocarpic crop plants, in combination with other environmentally considerate practices, to improve food security and their economic prospects.
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Affiliation(s)
- Jessica L Knapp
- Environment and Sustainability Institute University of Exeter Penryn Campus Penryn Cornwall TR10 9FE UK
| | - Lewis J Bartlett
- Centre for Ecology and Conservation University of Exeter, Penryn Campus Penryn Cornwall TR10 9FE UK
| | - Juliet L Osborne
- Environment and Sustainability Institute University of Exeter Penryn Campus Penryn Cornwall TR10 9FE UK
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Tiwari A, Vivian-Smith A, Ljung K, Offringa R, Heuvelink E. Physiological and morphological changes during early and later stages of fruit growth in Capsicum annuum. PHYSIOLOGIA PLANTARUM 2013; 147:396-406. [PMID: 22889158 DOI: 10.1111/j.1399-3054.2012.01673.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2011] [Revised: 05/23/2012] [Accepted: 06/03/2012] [Indexed: 05/23/2023]
Abstract
Fruit-set involves a series of physiological and morphological changes that are well described for tomato and Arabidopsis, but largely unknown for sweet pepper (Capsicum annuum). The aim of this paper is to investigate whether mechanisms of fruit-set observed in Arabidopsis and tomato are also applicable to C. annuum. To do this, we accurately timed the physiological and morphological changes in a post-pollinated and un-pollinated ovary. A vascular connection between ovule and replum was observed in fertilized ovaries that undergo fruit development, and this connection was absent in unfertilized ovaries that abort. This indicates that vascular connection between ovule and replum is an early indicator for successful fruit development after pollination and fertilization. Evaluation of histological changes in the carpel of a fertilized and unfertilized ovary indicated that increase in cell number and cell diameter both contribute to early fruit growth. Cell division contributes more during early fruit growth while cell expansion contributes more at later stages of fruit growth in C. annuum. The simultaneous occurrence of a peak in auxin concentration and a strong increase in cell diameter in the carpel of seeded fruits suggest that indole-3-acetic acid stimulates a major increase in cell diameter at later stages of fruit growth. The series of physiological and morphological events observed during fruit-set in C. annuum are similar to what has been reported for tomato and Arabidopsis. This indicates that tomato and Arabidopsis are suitable model plants to understand details of fruit-set mechanisms in C. annuum.
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Affiliation(s)
- Aparna Tiwari
- Horticultural Supply Chains, Plant Sciences Group, Wageningen University, PO Box 630, 6700 AP, Wageningen, The Netherlands
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Tiwari A, Vivian-Smith A, Voorrips RE, Habets MEJ, Xue LB, Offringa R, Heuvelink E. Parthenocarpic potential in Capsicum annuum L. is enhanced by carpelloid structures and controlled by a single recessive gene. BMC PLANT BIOLOGY 2011; 11:143. [PMID: 22018057 PMCID: PMC3214887 DOI: 10.1186/1471-2229-11-143] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2011] [Accepted: 10/21/2011] [Indexed: 05/22/2023]
Abstract
BACKGROUND Parthenocarpy is a desirable trait in Capsicum annuum production because it improves fruit quality and results in a more regular fruit set. Previously, we identified several C. annuum genotypes that already show a certain level of parthenocarpy, and the seedless fruits obtained from these genotypes often contain carpel-like structures. In the Arabidopsis bel1 mutant ovule integuments are transformed into carpels, and we therefore carefully studied ovule development in C. annuum and correlated aberrant ovule development and carpelloid transformation with parthenocarpic fruit set. RESULTS We identified several additional C. annuum genotypes with a certain level of parthenocarpy, and confirmed a positive correlation between parthenocarpic potential and the development of carpelloid structures. Investigations into the source of these carpel-like structures showed that while the majority of the ovules in C. annuum gynoecia are unitegmic and anatropous, several abnormal ovules were observed, abundant at the top and base of the placenta, with altered integument growth. Abnormal ovule primordia arose from the placenta and most likely transformed into carpelloid structures in analogy to the Arabidopsis bel1 mutant. When pollination was present fruit weight was positively correlated with seed number, but in the absence of seeds, fruit weight proportionally increased with the carpelloid mass and number. Capsicum genotypes with high parthenocarpic potential always showed stronger carpelloid development. The parthenocarpic potential appeared to be controlled by a single recessive gene, but no variation in coding sequence was observed in a candidate gene CaARF8. CONCLUSIONS Our results suggest that in the absence of fertilization most C. annuum genotypes, have parthenocarpic potential and carpelloid growth, which can substitute developing seeds in promoting fruit development.
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Affiliation(s)
- Aparna Tiwari
- Horticultural Supply Chains, Plant Sciences Group, Wageningen University, P.O. Box 630, 6700 AP Wageningen, The Netherlands
| | - Adam Vivian-Smith
- Molecular and Developmental Genetics, Institute of Biology, Leiden University, Sylvius Laboratory, Sylviusweg 72, 2333 BE Leiden, The Netherlands
- Norwegian Forest and Landscape Institute, Høgskoleveien 8, 1431 Ås, Norway
| | - Roeland E Voorrips
- Plant Research International, Plant Sciences Group, Wageningen University and Research Center, P.O. Box 16, 6700 AA Wageningen, The Netherlands
| | - Myckel EJ Habets
- Molecular and Developmental Genetics, Institute of Biology, Leiden University, Sylvius Laboratory, Sylviusweg 72, 2333 BE Leiden, The Netherlands
| | - Lin B Xue
- Department of Horticulture, Yangzhou University, Yangzhou, Jiangsu, PR China
| | - Remko Offringa
- Molecular and Developmental Genetics, Institute of Biology, Leiden University, Sylvius Laboratory, Sylviusweg 72, 2333 BE Leiden, The Netherlands
| | - Ep Heuvelink
- Horticultural Supply Chains, Plant Sciences Group, Wageningen University, P.O. Box 630, 6700 AP Wageningen, The Netherlands
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