Abstract：[Objective] The objective of this study was to investigate the effects of exogenous 24-epibrassinolide (EBR) on the photosynthetic physiology of cotton seedlings under low temperature and to provide basis for improving the cold tolerance of cotton by using EBR as growth regulator. [Method] Taking CCRI 60, Lumianyan 28 and Simian 3 as materials, a field experiment was carried out in Institute of Cotton Research of CAAS(Anyang county, Henan province). Before the first low temperature treatment, the cotton seedlings were sprayed with distilled water (Control) and different concentrations of EBR (0.1 mg·L－1 and 0.2 mg·L－1), respectively. After 3 days, the relative electrical conductivity, chlorophyll content, rapid chlorophyll fluorescence induction kinetic curve (OJIP) and fluorescence parameters were measured. [Result] Under low temperature, the relative conductivity of CCRI 60, Lumianyan 28 and Simian 3 spraying with EBR decreased by 17.7%～32.8% compared with control, and there was no significant difference between CCRI 60 and Lumianyan 28 in different concentrations of EBR treatments, but the relative conductivity of Simian 3 treating with 0.2 mg·L－1 EBR was significantly lower than those treatments with 0.1 mg·L－1 EBR . The chl a and chl b contents increased by 9.7%～32.6% and 15.0%～18.9%, respectively. The maximum photochemical efficiency of photosystemⅡ (Fv/FM) and photosynthetic performance index on absorption basis(PIABS) increased significantly. PIABS of CCRI 60 increase the maximum by 75.6% using 0.1 mg·L－1 EBR. Lumianyan 28 and Simian 3 increased the maximum by 101.1% and 265.6% using 0.2 mg·L－1 EBR, respectively; Absorbed photon flux per cross section (ABS/CSm), electron transport flux (further than QA) per active reactive center (ETo/RC) and probability for electron transport (φEo) are significantly increased. [Conclusion] Exogenous EBR can enhance the ability of low temperature tolerance of cotton seedlings and alleviate the inhibition of photosynthesis in cotton at low temperature. The study showed that 0.1 mg·L－1 EBR performs well in CCRI 60 and 0.2 mg·L－1 in Lumianyan 28 and Simian 3.
李淑叶,马慧娟,张思平, 等. 外源24-表油菜素内酯对低温胁迫下棉花幼苗光合生理的影响[J]. 棉花学报, 2018, 30(3): 252-260.
Li Shuye,Ma Huijuan,Zhang Siping, et al. Effects of Exogenous 24-epibrassinolide on Photosynthetic Physiology of CottonSeedlings under Low Temperature[J]. Cotton Science, 2018, 30(3): 252-260.
Wang Junjuan, Wang Shuai, Lu Xuke, et al. The effect of low temperature stress on the growth of upland cotton seedlings and a preliminary study of cold-resistance mechanisms[J]. Cotton Science, 2017, 29(2): 147-156.<br />
Liu Ao, Hu Zhengrong, Bi Aoyue, et al. Photosynthesis, antioxidant system and gene of bermudagrass in response to low temperature and salt stress[J]. Ecotoxicology, 2016, 25(8): 1445-1457.<br />
Liu Chunying, Chen Dayin, Gai Shupeng, et al. Effects of high and low temperature stress on PSⅡ function and physiologicalcharacteristics of peony leaves[J]. Chinese Journal of Applied Ecology, 2012, 23(1): 133-139.<br />
Wu Wei, Dai Haifang, Zhang Jushong, et al. Responses of photosynthetic characteristics of leaves of cotton seedlings to low temperature stress and recovery[J]. Chinese Journal of Plant Ecology, 2014, 38(10): 1124-1134.<br />
Abram S, Gert K, Reto S, et al. The role of low soil temperature in the inhibition of growth and PSⅡfunction during dark chilling in soybean genotypes of contrasting tolerance[J]. Physiologia Plantarum, 2007, 131(1): 89-105. <br />
Zhang Rongjia, Ren Fei, Bai Yanbo, et al. Advances in research on the effect of stress on PSⅡ based on rapid chlorophyll fluorescence kinetics[J]. Journal of Anhui Agri Sci, 2012, 40(70): 3858-3859, 3964.<br />
Rapacz M , Sasal M, Hazem K, et al. Is the OJIP test a reliable indicator of winter hardiness and freezing tolerance of common wheat and triticale under variable winter environments[J]. Plos One, 2015, 7(10): 1-18. <br />
Zushi K, Kajiwara S, Matsuzoe N. Chlorophyll a fluorescence OJIP transient as a tool to characterize and evaluate response to heat and chilling stress in tomato leaf and fruit[J]. Scientia Horticulturae, 2012, 148(4): 39-46. <br />
Priti K. Brassinosteroid-mediated stress responses[J]. Journal of Plant Growth Regulation, 2003, 22(4): 289-297.<br />
Steven C, Jenneth S. Brassinosteroids: essential regulators of plant growth and development[J]. Annual Review of Plant Physiology Plant Molecular Biology, 1998, 49: 427-451.<br />
Vardhini B V, Anjum A A. Brassinosteroids make plant life easier under abiotic stress mainly modulating major components of antioxidant defense system[J]. Frontiers in Environmental Science, 2015, 67(2): 1-15.<br />
Chang Dan, Yang Yi, Wang Yan, et al. Effect of 24-epibrassinolide on cotton seed germination under PEG and salt stress[J]. Acta Agricurae Boreali-occidentalis Sinica, 2015, 24(39): 96-101.<br />
Wu X X, He J, Zhu Z W, et al. Proection of photosynthesis and antioxidative system by 24-epibrassinolide in solanum melongena under cold stress[J]. Biologia Plantarum, 2014, 58(1): 185-188.<br />
Li Jie, Yang Ping, Kang Jungen, et al. Transcriptome analysis of pepper (Capsicum annuum) revealed a role of 24-epibrassinolide in response to chilling[J]. Frontiers in Plant Science, 2016, 7: 1-17.<br />
Jiang Yuping, Huang Lifeng, Cheng Fei, et al. Brassinosteroids accelerate recovery of photosynthetic apparatus from cold stress by balance the electron partitioning, carboxylation and redox homeostasis in cucumber[J]. Physiology Plant, 2013, 148(1): 133-145.<br />
Wang Xuekui. Principle and technology of plant physiological and biochemical test[M]. Beijing: Higher Education Press, 2008: 282-283.<br />
Stirbet A, Govindjee. On the relation between the kautsky effect（chlorophyll a fluorescence induction）and photosystem Ⅱ: Basics and applications of the OJIP fluorescence transient[J]. Journal of Photochemistry and Photobiology, 2011, 104: 236-257. <br />
Li Jing, Mao Shuchun, Han Yingchun, et al. Responses of soilless-substrate naked-seedling and transplanted cotton to temperature stress in recovering stage[J]. China Cotton, 2013, 40(1): 18-20.<br />
Hayat S, Hasan S A, Yusuf M, et al. Effect of 28-homobrasinolide on photosynthesis, fluorescence and antioxidant system in the presence or absence of salinity and temperature in Vigna radiata[J]. Environmental and Experimental Botany, 2010, 69(2): 105-112.<br />
Rapacz M. Chlorophyll a fluorescence transient during freezing and recovery in winter wheat[J]. Photosynthetica, 2007, 45(3): 409-418.<br />
Ensminger I, Busch F, Huner N P. Photostasis and cold acclimation: Sensing low temperature through photosynthesis[J]. Physiology Plant, 2006, 126(1): 28-44.<br />
李鹏民, 高辉远, Reto S. 快速叶绿素荧光诱导动力学在光合作用研究中的应用[J]. 植物生理与分子生物学报, 2005, 31(6): 559-566.<br />
Li Pengmin, Gao Huiyuan, Reto S. Application of the fast chlorophyll fluorescence induction dynamics in photosynthesisstudy[J]. Physiology Plant, 2006, 126(1): 28-44.<br />
Hu W H, Wu Z. Chill-induced inhibition of photosynthesis was alleviated by 24-epibrassinolide pretreatment in cucumber during chilling and subsequent recovery[J]. Photosynthetica, 2010, 48(4): 537-544.<br />
Faridduudin Q,Yusuf M, Ahmad I, et al. Brassinosteroids and their role in response of plants to abiotic stresses[J]. Biologia Plantarum, 2014, 58(1): 9-17.<br />
Divi U K, Krishna P. Brassinoteroid: a biotechnological target for enhancing crop yield and stress tolerance[J]. New Biotechnology, 2009, 26(3): 131-136.<br />
Hao Huifang, Fan Yuexian, Li Shengquan. Effects of cold acclimation on chilling tolerance and leaf ultrastructure in cotton seedlings[J]. Cotton Science, 2017, 29(3): 268-273.<br />
Giffith M, Brown G N, Huner N. Structural changes in thylakoid proteins during cold acclimation and freezing of winter rye[J]. Plant Physiology, 1982, 70(2): 418-423.<br />
Li Jie, Yang Ping, Gan Yantai. Brassinosteroid alleviates chilling-induced oxidative stress in pepper by enhancing antioxidation systems and maintenance of photosystemⅡ[J]. Acta Physiol Plant, 2015, 37(222): 1-11.<br />
Li Taotao, Gao Yongfeng, Ma Xuan, et al. Effects of exogenous brassinolide on photosynthetic physiology of three poplar populations under drought, salt and copper stress[J]. Genomics and Applied Biology, 2016, 35(1): 218-226.