To explore the photosynthetic response of short-term high-temperature treatments to the leaves of different grape varieties (Shenyue and Shenfeng), we performed 45°C treatments on annual potted grapes in an artificial climate chamber to simulate the summer high-temperature period. We measured the rapid A-Ci response curve, 1,5-ribulose bisphosphate carboxylase/oxygenase (Rubisco) activity and chlorophyll a fluorescence. Photosynthetic performance-related parameters of grapevine leaves were found to be adversely affected by high temperature; the maximum rates of carboxylation of Rubisco and ribulose diphosphate regeneration and Rubisco activity were all significantly reduced. The JI of the JIP-test curve disappeared under high-temperature treatment, and the K peak appeared, indicating that the oxygen-evolving complex (OEC) had been destroyed. Principal component analysis showed that PSII activity (F_v/F_m, DF_ABS, φ_Eo, ABS/RC) was greatly affected by high temperature. It was also found that the Rubisco activity and OEC destruction strength were greater in one of the cultivars, and we were able to determine heat resistance based on the phenotype and photosynthetic performance. It can be seen from the above that Shenyue leaves have higher heat tolerance and stronger photosynthetic performance than Shenfeng leaves. This shows that photosynthetic performance is strongly correlated with a grapevine's tolerance to abiotic stress.

中文翻译：

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短时高温处理对不同耐热葡萄品种光合性能的影响

为了探索短期高温处理对不同葡萄品种（神月和神丰）叶片的光合响应，我们在人工气候室中对一年生盆栽葡萄进行了 45°C 处理，以模拟夏季高温期。我们测量了快速 A-Ci 响应曲线、1,5-核酮糖二磷酸羧化酶/加氧酶 (Rubisco) 活性和叶绿素 a 荧光。发现葡萄叶片的光合性能相关参数受到高温的不利影响；Rubisco的最大羧化率和核酮糖二磷酸再生和Rubisco活性均显着降低。JIP-test曲线的JI在高温处理下消失，出现K峰，表明析氧复合物（OEC）已被破坏。F _v / F _m , DF _ABS , φ _Eo , ABS/RC) 受高温影响很大。还发现其中一个品种的 Rubisco 活性和 OEC 破坏强度更大，我们能够根据表型和光合性能确定耐热性。由上可知，神月叶比神枫叶具有更高的耐热性和更强的光合性能。这表明光合性能与葡萄树对非生物胁迫的耐受性密切相关。