Optimized nitrogen management enhances lodging resistance of rice and its morpho-anatomical, mechanical, and molecular mechanisms

Abstract

Increasing evidence shows that improved nitrogen management can enhance lodging resistance and lower internodes play a key role in the lodging resistance of rice. However, little is known about the cellular and molecular mechanisms underlying the enhanced lodging resistance under improved nitrogen management. In the present study, two rice varieties, with contrasting lodging resistance, were grown under optimized N management (OPT) and farmers’ fertilizer practices. Under OPT, the lower internodes of both cultivars were shorter but the upper internodes were longer, while both culm diameter and wall thickness of lower internodes were dramatically increased. Microscopic examination showed that the culm wall of lower internodes under OPT contained more sclerenchyma cells beneath epidermis and vascular bundle sheath. The genome-wide gene expression profiling revealed that transcription of genes encoding cell wall loosening factors was down-regulated while transcription of genes participating in lignin and starch synthesis was up-regulated under OPT, resulting in inhibition of longitudinal growth, promotion in transverse growth of lower internodes and enhancement of lodging resistance. This is the first comprehensive report on the morpho-anatomical, mechanical, and molecular mechanisms of lodging resistance of rice under optimized N management.

Genotyping-By-Sequencing Based Investigation of Population Structure and Genome Wide Association Studies for Seven Agronomically Important Traits in a Set of 346 Oryza Rufipogon Accessions

“…The role of NmrA-like domain containing proteins, Lectin like receptor kinases in cell differentiation, cell division, shoot/ ber development has been documented by Reiner et al 2016 andZuo et al 2004 explaining the association of the signi cant markers with CT. Similarly, the function of glycosyl hydrolase family proteins, a type of cell wall degrading enzyme, in the control of longitudinal and transverse growth has been linked to CT and PH in uencing lodging resistance (Pan et al 2019). Zhou et al 2016 have established the interaction of OsRLCK57 with OsBRI1 (a rice BR receptor) to affect rice panicle branching, explaining association with PB.…”

Genetic analyses of lodging resistance and yield provide insights into post‐Green‐Revolution breeding in rice

“…For each culm, the gravity‐centre height (the distance from culm base to gravity‐centre) was measured using a ruler, and the balance fulcrum of a horizontally put culm with panicle, leaf and leaf sheath was marked as the gravity‐centre. The internodes were counted from culm base upward (Pan et al ., 2019; Zhong et al ., 2020). The first internode length (IL1), the second internode length (IL2) and the panicle length (PL) were measured using a ruler (Figure 1a‐c).…”

Optimized split nitrogen fertilizer increase photosynthesis, grain yield, nitrogen use efficiency and water use efficiency under water-saving irrigation

“…With regards to wheat cultivation, nitrogen, as an essential macronutrient, is required more consistently and in larger amounts than any other nutrient 8 . Under application of nitrogen fertilizer in wheat production can prolong the grain-filling stage and improve photosynthesis capacity, thereby enhancing grain yield 9 .…”