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Agronomic measures are the key to promote the sustainable development of ratoon rice by reducing the damage from mechanical crushing to the residual stubble of the main crop, thereby mitigating the impact on axillary bud sprouting and yield formation in ratoon rice. This study used widely recommended conventional rice Jiafuzhan and hybrid rice Yongyou 2640 as the test materials to conduct a four-factor block design field experiment in a greenhouse of the experimental farm of Fujian Agricultural and Forestry University, China from 2018 to 2019. The treatments included fertilization and no fertilization, alternate wetting and drying irrigation and continuous water flooding irrigation, and plots with and without artificial crushing damage on the rice stubble. At the same time, a 13C stable isotope in-situ detection technology was used to fertilize the pot experiment. The results showed significant interactions among varieties, water management, nitrogen application and stubble status. Relative to the long-term water flooding treatment, the treatment with sequential application of nitrogen fertilizer coupled with moderate field drought for root-vigor and tiller promotion before and after harvesting of the main crop, significantly improved the effective tillers from low position nodes. This in turn increased the effective panicles per plant and grains per panicle by reducing the influence of artificial crushing damage on rice stubble and achieving a high yield of the regenerated rice. Furthermore, the partitioning of 13C assimilates to the residual stubble and its axillary buds were significantly improved at the mature stage of the main crop, while the translocation rate to roots and rhizosphere soil was reduced at the later growth stage of ratooning season rice. This was triggered by the metabolism of hormones and polyamines at the stem base regulated by the interaction of water and fertilizer at this time. We therefore suggest that to achieve a high yield of ratoon rice with low stubble height under mechanized harvesting, the timely application of nitrogen fertilizer is fundamental, coupled with moderate field drying for root-vigor preservation and tiller promotion before and after the mechanical harvesting of the main crop.

Crop perennialization has garnered global attention recently due to its role in sustainable agriculture. However, there is still a lack of detailed information regarding perennial rice’s regenerative characteristics and physiological mechanisms in crop ratooning systems with different rice stubble heights. In addition, the response of phytohormones to varying stubble heights and how this response influences the regenerative characteristics of ratoon rice remains poorly documented. Here, we explored the regenerative characteristics and physiological mechanisms of an annual hybrid rice, AR2640, and a perennial rice, PR25, subjected to different stubble heights (5, 10, and 15 cm). The response of phytohormones to varying stubble heights and how this response influences the regenerative characteristics of ratoon rice were also investigated. The results show that PR25 overwintered successfully and produced the highest yield, especially in the second ratoon season, mainly due to its extended growth duration, higher number of mother stems, tillers at the basal nodes, higher number of effective panicles, and heavier grain weight when subjected to lower stubble heights. Further analysis revealed that PR25 exhibited a higher regeneration rate from the lower-position nodes in the stem with lower stubble heights. this was primarily due to the higher contents of phytohormones, especially auxin (IAA) and gibberellin (GA3) at an early stage and abscisic acid (ABA) at a later stage after harvesting of the main crop. Our findings reveal how ratoon rice enhances performance based on different stubble heights, which provides valuable insights and serves as crucial references for delving deeper into cultivating high-yielding perennial rice.

Objective To investigate the relationship between the expression of Zeste White 10 interactor（ZWINT）and Cyclin-dependent kinase 2（CDK2）and clinicopathological features in breast cancer，and evaluate their pathological diagnostic values in breast cancer. Methods GEPIA database was utilized to analyze the difference in the expression of ZWINT between breast cancer and normal breast tissues and assess the correlation between ZWINT and CDK2 expression in breast cancer. Kaplan-Meier Plotter database was employed to predict the relationship between ZWINT expression and clinical prognosis of breast cancer patients. Paraffin-embedded pathological specimens of 84 cases of breast cancer and paired paracancerous tissues and fresh specimens of 20 cases of breast cancer and paired paracancerous tissues were collected. Quantitative real-time polymerase chain reaction（RT-qPCR）and immunohistochemical staining were used to detect the expression levels of ZWINT and CDK2 mRNA and protein in breast cancer and paracancerous normal breast tissues，to analyze the relationship between ZWINT and CDK2 expression levels and clinicopathological features of breast cancer. Association analysis was used to analyze the correlation between ZWINT and CDK2. Receiver operating characteristic（ROC）curve was delineated to evaluate the values of ZWINT and CDK2 in the pathological diagnosis of breast cancer. Results The results of database analysis showed that ZWINT was highly expressed in breast cancer tissues and there was a positive correlation between the expression of ZWINT and CDK2 in breast cancer（rs = 0.600，P < 0.001）. The expression of ZWINT was closely correlated with clinical prognosis of breast cancer patients（all P < 0.05）. The test results of 84 cases showed that the expression levels of ZWINT and CDK2 mRNA and protein in breast cancer tissues were higher than those in para-carcinoma tissues（both P < 0.05），and high expression was closely correlated with tumor size，tumor stage and lymph node metastasis（all P < 0.05）. Association analysis revealed that the degree of association of Φ and Cramer V coefficient test under symmetric measurements was the same as 0.322（P = 0.003），while the column linkage number was 0.306（P = 0.003）. The expression levels of ZWINT and CDK2 proteins were closely correlated. The areas under the ROC curve of ZWINT and CDK2 were 0.886 and 0.818，which yielded high diagnostic values for breast cancer. Conclusions ZWINT and CDK2 expression levels are closely correlated the occurrence，development and prognosis of breast cancer. Detection of ZWINT and CDK2 contributes to pathological diagnosis of breast cancer.