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Jun 2024, Volume 3 Issue 2
    
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  • Wenbin Xu, Yuanmei Miao, Jie Kong, Keith Lindsey, Xianlong Zhang, Ling Min
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    With global warming, crop plants are challenged by heat stress during reproductive growth, leading to male sterility and yield reduction. The balance between reactive oxygen species (ROS) generation and scavenging is disrupted by stress, resulting in oxidative stress which is harmful to crop growth. However, recent advances have shown that ROS signaling via proteins that sense the redox state is positive for plant performance under stress. ROS signaling is also involved in regulating anther development, such as timely tapetum degeneration. We summarize recent progress in uncovering the mechanism of heat stress effects on ROS homeostasis and discuss the relationship between oxidative stress and metabolic disorder, which is often observed during anther development under heat stress. We propose experimental and breeding strategies to improve field crop tolerance to heat stress.
  • Daisuke Sugiura, Yin Wang, Masaru Kono, Yusuke Mizokami
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    Exploring the impact of elevated CO2 on photosynthesis is vital for understanding plant responses to climate change. In C3 plants, elevated CO2 concentrations generally enhance CO2 assimilation by increasing chloroplast CO2 concentration. However, the underlying mechanisms are complex since photosynthesis involves multiple physiological processes operating at different time scales and varying among plant species. In this review, we focused on the responses of key photosynthetic processes in crop, including CO2 diffusion conductances such as stomatal conductance (gs), mesophyll conductance (gm), photochemical reactions, the Calvin-Benson cycle, and related metabolic pathways. Short-term exposure to elevated CO2 often decreases gs and gm while increasing the electron transport rate. However, long-term exposure to elevated CO2 can decrease photosynthetic capacity due to coordinated downregulation of multiple processes, particularly when the sink‒source ratio declines. To enhance plant productivity under elevated CO2, it is crucial to maintain or enhance sink activity and understand the CO2 response mechanisms at the molecular, physiological, and morphological levels. This review provides an update on the short- and long-term responses of gs, gm, electron transport system, and carbon assimilation metabolism to elevated CO2. Furthermore, it offers a perspective on improving crop production in the future with elevated CO2 levels.
  • Hehe Gu, Zhifeng Lu, Tao Ren, Jianwei Lu
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    The earliest occurrence of chlorosis at the tips of the oldest leaves is widely recognized as a reliable indicator for diagnosing potassium (K) deficiency and determining the need for K fertilizer. However, hidden K deficiency, typically associated with a decrease in individual leaf photosynthetic area, precedes the onset of visible yellowing symptoms. These concealed symptoms pose challenges for the early diagnosis of K deprivation in plants. The two distinct stages of deficiency exhibit different photosynthetic performances, which are speculated to be closely linked to the subcellular K+ distribution. This minireview focuses on investigating K+ dynamics across subcellular compartments, along with the involvement of functional transporter proteins and ion channels during K deficiency. We propose potential mechanisms by which subcellular K+ regulates photosynthetic capacity under both hidden and visual K deficiency conditions, which sheds new light on the diagnosis of K deficiency. Additionally, future research prospects and areas deserving further investigation are also outlined.
  • Zhaohong Lu, Jing Gao, Qi Wang, Zili Ning, Xianming Tan, Yi Lei, Jie Zhang, Jiaqi Zou, Lingxuan Wang, Chenyao Yang, Wenyu Yang, Feng Yang
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    Efficient solar energy utilization is a crucial determinant of crop yield formation. Moreover, various planting methods have dissimilar impacts on crop solar energy utilization and its measurement methods. This study examined the differences in solar energy utilization between monoculture and intercropping by considering density configuration, plant type arrangement, timing schedule, and spatial layout. We further evaluated the traditional methodologies versus remote sensing technology for solar energy measurements and described the differences in calculation methods for monoculture and intercropping, drawing from the photosynthesis model. Additionally, we discussed the potential advantages and limitations of employing remote sensing technology for the monitoring and prediction of solar energy utilization in field crops.
  • Boya Liu, Xuming Wang, Qi Liu, Yining Xu, Ashraf Muhammad Arslan, Dingming Zheng, Lei Li, Xiaoying Gong
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    Leaf day respiration rate (RL) plays a crucial role in the global carbon cycle. However, RL of C4 species has not been sufficiently studied and its response to environmental factors is largely unknown. This work studied the response of RL of three C4 species, Setaria viridis, Sorghum sudanense, and Zea mays, to alterations in the vapour pressure deficit (VPD) and irradiance of the growth environment. RL was estimated using the Kok method (RL Kok) and an improved method that combined gas exchange and chlorophyll fluorescence measurements (RL Yin). On average, shade treatment led to a 24% reduction in RL Yin and a 20% reduction in respiration in the dark (RDk), while a consistent VPD effect on RL was not observed. RL and RDk were positively correlated with nitrogen content per leaf area and net CO2 assimilation rate but were not correlated with the capacity of carboxylation enzymes. We found a non-significant light inhibition of respiration (1 ± 2%), contradicting the assumption that respiration is inhibited by light and affected by light intensity. Our findings indicate that assuming RL to be equal to RDk at the same temperature is a straightforward but reliable approach to model respiration of the examined C4 species.
  • Funian Zhao, Qiang Zhang, Jun Lei, Heling Wang, Kai Zhang, Yue Qi
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    Understanding how environmental factors influence the responsiveness of crop yield to growing season precipitation (GSP) can reduce the risk of yield fluctuations, ensuring stable crop production. This study involved the cultivation of rainfed potatoes at three locations within the climatic transition zone of Northwest China. We employed stepwise linear regression and machine learning techniques to pinpoint the key environmental factors influencing potato tuber yield and the yield-precipitation relationship. The slope of the water-limited yield potential relationship for potatoes was determined to be 172.1 kg ha-1 mm-1, with an intercept at 121.2 mm. The potato tuber yield exhibited an upward trend with increasing GSP but declined once the precipitation exceeded 400 mm. However, GSP alone explained up to 30% of the variability in potato tuber yield. Factors such as soil moisture at planting, maximum temperatures during the tuber stolon initiation and bulking stages, diurnal temperature fluctuations at maturity, and excessive precipitation events during the growing season significantly influenced potato tuber yield, and consequently, the relationship between yield and GSP. Conversely, climatic factors accounted for more than 63% of the variation in potato tuber yield, with the multiple linear regression model yielding the best results. This was especially evident when the yield-precipitation relationship was categorized into two groups based on the amount and distribution of GSP, maximum temperature, and radiation levels. This analysis suggested that preventing unnecessary water evaporation when precipitation is low, improving drainage when precipitation is high, and planting potato on an optimal date can advance potato production.