CaHSP16.4, a small heat shock protein gene in pepper, is involved in heat and drought tolerance
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Environmental stress affects growth and development of crops, and reduces yield and quality of crops. To cope with environmental stressors, plants have sophisticated defense mechanisms, including the HSF/HSP pathway. Here, we identify the expression pattern of CaHSP16.4 in thermo-tolerant and thermo-sensitive pepper (Capsicum annuum L.) lines. Under heat stress, R9 thermo-tolerant line had higher CaHSP16.4 expression level than the B6 thermo-sensitive line. Under drought stress, expression pattern of CaHSP16.4 was dynamic. Initially, CaHSP16.4 was downregulated then CaHSP16.4 significantly increased. Subcellular localization assay showed that CaHSP16.4 localizes in cytoplasm and nucleus. In the R9 line, silencing of CaHSP16.4 resulted in a significant increase in malonaldehyde content and a significant reduction in total chlorophyll content, suggesting that silencing of CaHSP16.4 reduces heat and drought stresses tolerance. Overexpression of CaHSP16.4 enhances tolerance to heat stress in Arabidopsis. Under heat stress, the survival rate of CaHSP16.4 overexpression lines was significantly higher than wild type. Furthermore, under heat, drought, and combined stress conditions, the CaHSP16.4-overexpression lines had lower relative electrolytic leakage and malonaldehyde content, higher total chlorophyll content, and higher activity levels of superoxide dismutase, catalase, ascorbic acid peroxidase, and glutathione peroxidase compared to wild type. Furthermore, the expression levels of the stress response genes in the overexpression lines were higher than the wild type. These results indicate that the overexpression of CaHSP16.4 enhances the ability of reactive oxygen species scavenging under heat and drought stress.
KeywordsCaHSP16.4 Pepper Arabidopsis Heat stress Drought stress ROS-scavenging system
LH and ZG designed the experiments. LH, GC, AK, AW, QY, and SY performed the research. LH drafted the manuscript. ZG revised the paper. ZG and DL contributed reagents/materials/analysis tools. All authors read and approved the final manuscript.
This work was supported through the funding from the National Natural Science Foundation of China (No. U1603102), National Key R&D Program of China (No. 2016YFD0101900), and the Independent Innovation Fund Project of Agricultural Science and Technology in Jiangsu (No.CX (17) 3040).
Compliance with ethical standards
Competing financial interests
The authors declare that they have no competing interests.
- Basha E, Lee GJ, Breci LA, Hausrath AC, Buan NR, Giese KC, Vierling E (2004) The identity of proteins associated with a small heat shock protein during heat stress in vivo indicates that these chaperones protect a wide range of cellular functions. J Biol Chem 279:7566–7575. https://doi.org/10.1074/jbc.M310684200 CrossRefGoogle Scholar
- Flohé L, Günzler WA (1984) Assay of glutathione peroxidase. Methods Enzymol 105:104–121Google Scholar
- Fragkostefanakis S, Mesihovic A, Simm S, Paupière MJ, Hu Y, Paul P, Mishra SK, Tschiersch B, Theres K, Bovy A, Schleiff E, Scharf KD (2016) HsfA2 controls the activity of developmentally and stress-regulated heat stress protection mechanisms in tomato male reproductive tissues. Plant Physiol 170:2461–2477. https://doi.org/10.1104/pp.15.01913 CrossRefGoogle Scholar
- Guo M, Zhai YF, Lu JP, Chai L, Chai WG, Gong ZH et al (2014) Characterization of CaHsp70-1, a pepper heat-shock protein gene in response to heat stress and some regulation exogenous substances in Capsicum annuum L. Int J Mol Sci 15:19741–19759. https://doi.org/10.3390/ijms151119741 CrossRefGoogle Scholar
- IPCC (2007) Climate change 2007: the physical science basis. In: Solomon S, Qin D, Manning M, Chen Z, Marquis M, Averyt KB, Tignor M, Miller HL (eds) Contribution of Working Group I to the 4th Assessment Report of the IPCC. Cambridge University Press, Cambridge nGoogle Scholar
- Lin M, Chai K, Ko S, Kuang L, Lur H, Charng YY (2014) A positive feedback loop between HEAT SHOCK PROTEIN101 and HEAT STRESS-ASSOCIATED 32-KD PROTEIN modulates long-term acquired thermotolerance illustrating diverse heat stress responses in rice varieties. Plant Physiol 164:2045–2053. https://doi.org/10.1104/pp.113.229609 CrossRefGoogle Scholar
- Lopes-Caitar VS, de Carvalho MC, Darben LM, Kuwahara MK, Nepomuceno AL, Dias WP et al (2013) Genome-wide analysis of the Hsp20 gene family in soybean: comprehensive sequence, genomic organization and expression profile analysis under abiotic and biotic stresses. BMC Genomics 14:577. https://doi.org/10.1186/1471-2164-14-577 CrossRefGoogle Scholar
- Ma BP, Lu MH, Gong ZH (2013) Responses of growth and physiology of pepper (Capsicum annuum L.) seedlings to high temperature stress. J Northwest A&F Univ 41:1–7Google Scholar
- Nakano Y, Asada K (1981) Hydrogen peroxide scavenged by ascorbate—specific peroxidase in spinach chloroplasts. Plant Cell Physiol 22:867–880Google Scholar
- Pucciariello C, Perata P (2012) How plants sense low oxygen. Plant Signal Behav 7(7): 813–816. https://doi.org/10.4161/psb.20322
- Schramm F, Larkindale J, Kiehlmann E, Ganguli A, Englich G, Vierling E, von Koskull-Döring P (2008) A cascade of transcription factor DREB2A and heat stress transcription factor HsfA3 regulates the heat stress response of Arabidopsis. Plant J 53:264–274. https://doi.org/10.1111/j.1365-313X.2007.03334.x CrossRefGoogle Scholar
- Sun X, Sun C, Li Z, Hu Q, Han L, Luo H (2016) AsHSP17, a creeping bent grass small heat shock protein modulates plant photosynthesis and ABA-dependent and independent signaling to attenuate plant response to abiotic stress. Plant Cell Environ 39:1320–1337. https://doi.org/10.1111/pce.12683 CrossRefGoogle Scholar
- Yoshida T, Ohama N, Nakajima J, Kidokoro S, Mizoi J, Nakashima K, Maruyama K, Kim JM, Seki M, Todaka D, Osakabe Y, Sakuma Y, Schöffl F, Shinozaki K, Yamaguchi-Shinozaki K (2011) Arabidopsis HsfA1 transcription factors function as the main positive regulators in heat shock-responsive gene expression. Mol Gen Genomics 286:321–332. https://doi.org/10.1007/s00438-011-0647-7 CrossRefGoogle Scholar
- Zhong L, Zhou W, Wang H, Ding S, Lu Q, Wen X et al (2013) Chloroplast small heat shock protein HSP21 interacts with plastid nucleoid protein pTAC5 and is essential for chloroplast development in Arabidopsis under heat stress. Plant Cell 25:2925–2943. https://doi.org/10.1105/tpc.113.111229 CrossRefGoogle Scholar