Negi Pooja, Pandey Manish, Paladi Radha K, Majumdar Arnab, Pandey Shailaja P, Barvkar Vitthal T, Devarumath Rachayya, Srivastava Ashish K
Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre, Mumbai, India.
Homi Bhabha National Institute, Mumbai, India.
Plant Cell Environ. 2025 Jun;48(6):4668-4684. doi: 10.1111/pce.15424. Epub 2025 Mar 7.
Sugarcane (Saccharum officinarum L.) is an economically important long-duration crop which is currently facing concurrent heat waves and soil salinity. The present study evaluates an inducible salt-tolerant sugarcane mutant M4209, developed via radiation-induced mutagenesis of elite check variety Co 86032, under heat (42/30°C; day/night), NaCl (200 mM) or heat + NaCl (HS)-stress conditions. Though heat application significantly improved plant growth and biomass in both genotypes, this beneficial impact was partially diminished in Co 86032 under HS-stress conditions, coinciding with higher Na accumulation and lower triacylglycerol levels. Besides, heat broadly equalised the negative impact on NaCl stress in terms of various physiological and biochemical attributes in both the genotypes, indicating its spaciotemporal advantage. The simultaneous up- and downregulation of antagonistic regulators, epidermal patterning factor (EPF) 9 (SoEPF9) and SoEPF2, respectively attributed to the OSD (Open Small Dense) stomatal phenotype in M4209, which resulted into enhanced conductance, transpirational cooling and gaseous influx. This led to improved photoassimilation, which was supported by higher plastidic:nonplastidic lipid ratio, upregulation of SoRCA (Rubisco activase) and better source strength, resulting in overall plant growth enhancement across all the tested stress scenarios. Taken together, the present study emphasised the knowledge-driven harnessing of stomatal-photosynthetic synergy for ensuring global sugarcane productivity, especially under "salt-heat" coupled stress scenarios.
甘蔗（Saccharum officinarum L.）是一种具有重要经济价值的长期作物，目前正面临着同时出现的热浪和土壤盐渍化问题。本研究评估了通过对优良对照品种Co 86032进行辐射诱变培育出的一种可诱导耐盐甘蔗突变体M4209，在高温（42/30°C；白天/夜晚）、NaCl（200 mM）或高温+NaCl（HS）胁迫条件下的表现。虽然施加高温显著改善了两种基因型的植物生长和生物量，但在HS胁迫条件下，Co 86032的这种有益影响部分减弱，同时伴有较高的钠积累和较低的三酰甘油水平。此外，在各种生理和生化特性方面，高温在很大程度上抵消了NaCl胁迫对两种基因型的负面影响，表明其时空优势。拮抗调节因子表皮模式因子（EPF）9（SoEPF9）和SoEPF2分别同时上调和下调，这归因于M4209中的开放小致密（OSD）气孔表型，从而导致气孔导度增加、蒸腾冷却增强和气态流入增加。这促进了光同化作用，其得到了较高的质体：非质体脂质比率、SoRCA（核酮糖-1,5-二磷酸羧化酶/加氧酶激活酶）上调和更好的源强度的支持，从而在所有测试的胁迫情况下总体上促进了植物生长。综上所述，本研究强调了利用知识驱动的气孔-光合协同作用来确保全球甘蔗生产力，特别是在“盐-热”耦合胁迫情况下。
