Rahmat Bayu Pradana Nur, Octavianis Grace, Budiarto Rahmat, Jadid Nurul, Widiastuti Ani, Matra Deden Derajat, Ezura Hiroshi, Mubarok Syariful
Master Program of Agronomy, Faculty of Agriculture, Universitas Padjadjaran, Sumedang 45363, Indonesia.
Under Graduate Program of Agrotechnology, Faculty of Agriculture, Universitas Padjadjaran, Sumedang 45363, Indonesia.
Plants (Basel). 2023 Jan 13;12(2):378. doi: 10.3390/plants12020378.
Tomato is one of the most widely consumed horticultural products. However, tomato is very sensitive to changes in temperature. Daily average temperatures above 32 °C severely reduced tomato plant growth, development, and productivity. Therefore, climate change-induced global warming is a major threat to future tomato production. Good photosynthetic capability under heat stress conditions is known to be a major sign of heat tolerance. Tomato INDOLE-ACETIC-ACID (SlIAA9) is a transcriptional repressor in auxin signaling. SlIAA9 mutation caused heightened endogenous auxin response and biosynthesis within plant tissues. In this study, we studied the photosynthetic capability of iaa9-3 and iaa9-5 mutants under heat-stress conditions. We discovered that both iaa9-3 and iaa9-5 could maintain their photosynthetic capability after 14 days of heat treatment (>40 °C), differing from Wild Type-Micro-Tom (WT-MT) tomato. Both iaa9 mutants had higher net photosynthetic rate, stomatal conductance, leaf total chlorophyll, leaf carotenoids, Fv/Fm value, and lower leaf MDA than WT-MT. These results suggested that the SlIAA9 mutation benefits plant adaptation to heat stress.
番茄是消费最为广泛的园艺产品之一。然而，番茄对温度变化非常敏感。日平均温度高于32°C会严重降低番茄植株的生长、发育和生产力。因此，气候变化导致的全球变暖是未来番茄生产的主要威胁。已知在热胁迫条件下具有良好的光合能力是耐热性的主要标志。番茄吲哚-3-乙酸（SlIAA9）是生长素信号传导中的转录抑制因子。SlIAA9突变导致植物组织内源性生长素反应和生物合成增强。在本研究中，我们研究了iaa9-3和iaa9-5突变体在热胁迫条件下的光合能力。我们发现，与野生型微型番茄（WT-MT）不同，iaa9-3和iaa9-5在40°C以上热处理14天后仍能保持其光合能力。两个iaa9突变体的净光合速率、气孔导度、叶片总叶绿素、叶片类胡萝卜素、Fv/Fm值均高于WT-MT，叶片丙二醛含量低于WT-MT。这些结果表明，SlIAA9突变有利于植物适应热胁迫。
